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Oil in the Sea: Inputs, Fates, and Effects (1985)

Chapter: Part A: Chemical Methods

« Previous: 3. CHEMICAL AND BIOLOGICAL METHODS
Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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Suggested Citation:"Part A: Chemical Methods." National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press. doi: 10.17226/314.
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94 PART A Chemical Methods ~ NTRODUCTION There have been many signif icant advances in the application of chemical analyses to all aspects of petroleum pollution in the marine environment since the last National Research Council (1975) publication. However, no one method of analysis can measure all components of petroleum or answer all requirements for research and monitoring. Many techniques have been applied to oil spill studies, monitoring of long term sources of input such as Sewage effluents and production platforms, and experi- mental studies of the fate and effects of petroleum in the marine environment. Concurrently, new equipment has been developed for the variety of sampling problems that have been encountered, and instru- mental techniques for real-time monitoring of petroleum components in water near oil spills have been successfully tested. The analytical methods applied to oil spill studies usually combine low resolution but relatively easily applied techniques, such as ultraviolet (W) fluorescence spectrometry, with high resolution but more costly and time-consuming techniques, such as glass capillary/gas chromatography/mass spectrometry (GC2/MS) computer systems. This also applies to monitoring of chronic inputs and analytical chemistry in support of exper imental studies of fate and effects. Two important issues that have sometimes been overlooked are (a) choosing the method (s) that will satisfactorily solve the analytical problem at hand; for example, gross levels of hydrocarbons in tissues as determined by nonspecific measurements such as ultraviolet fluor- escence have minimal use when the problem is to distinguish between chronic background hydrocarbon pollution of combustion origin, chronic petroleum pollution, biogenic hydrocarbon inputs, and additions of petroleum hydrocarbons from a recent oil spill; and (b) quality control within and between laboratories. This latter point has been emphasized repeatedly as a priority item, but funding practices by federal agencies generally paid scant attention to this problem until a few years ago. The 1975 NRC report called attention to this, and recently the American Chemical Society (ACS) has issued guidelines for data acquisition and data quality evaluation in environmental chemistry (Keith et al., 1983), which address this fundamental issue for all types of environmental analytical chemistry. The current status of quality control and laboratory intercomparison is not yet adequate to accomplish detailed comparisons of data sets from different laboratories or to be sure which specific chemicals in various petroleum fractions are responsible for observed effects. Generally, only compar isons of qual itative trends or large differences of factors of 10 or more are valid within quality control or inter- laboratory comparison experiences proof to 1979-1980. Although progress has been made, much more needs to be accomplished. Two major developments in our knowledge of inputs, fates, and effects of petroleum in the marine environment since the 1973 litera- ture review for the 1975 NRC report have an important bearing on

95 analytical chemistry considerations. First, studies of polycyclic aromatic hydrocarbon sources and fates over the past ~ O years have increased markedly and have revealed the global significance of chronic low level polynuclear aromatic hydrocarbons (PAM) inputs related to the incomplete high temperature combustion of fossil fuels. In many cases, analytical methods must try to distinguish between petroleum PAR inputs and pyrogenic PAH inputs. Second, present evidence substantiates a concern expressed in the 1975 NRC report that petroleum hydrocarbons readily undergo structural alterations by photochemical and biochemical metabolic oxidation. Postspill analytical programs based only on hydro- carbon measurements in seawater, sediments, and tissues cannot measure an important set of transformation products. Acute needs have developed (1) to manage data and make them acces- sible (needs that have only occasionally been addressed in specific programs), (2) to evaluate existent data much more thoroughly to enable future efforts to be more targeted, and (3) to link divergent analytical developments. This latter concern arises from the fact that varieties of analytical techniques are being separately developed for petroleum chemistry research, marine chemistry research, forensic applications (e.g., U.S. Coast Guard techniques!, general environmental chemistry research, and environmental regulatory or surveillance (e.g., U.S. Environmental Protection Agency (EPA) priority pollutant) methodologies. An overview of the literature confirms this and raises concerns that, in our efforts to monitor the environment, the methods being developed for and information derived from the various programs are diverging. This is apparent in the groups of marine chemistry and other environ- mental chemistry literature, citations from one omitting relevant literature from the other. Regulatory definitions of petroleum hydrocarbons must be more firmly based in current knowledge of the composition of petroleum inputs, fates, and effects in the environment. The review of analytical techniques, methods, and strategies that follows has drawn from marine and nonmarine analytical chemistry and organic biogeochemical studies alike. Due to the great pool of recent literature, attempts have been made to include mainly post-1975 litera- ture unless only pre-1975 information Is available. AS no single literature reference comprehensively covers many of the topics dis- cussed, a number of references are cited in many cases. Several recent reviews have aided in this preparation and should be consulted for additional details: Petrakis and Weiss (1980), R.C. Clark and Brown (1977), Farrington et al. (1976a, 1980), R.A. Brown and Weiss (1978), Pancirov and Brown (1981), and Malins et al. (1980~. SAMPLING AND SAMPLE PRESERVATION The nature and the quality of information derived from marine environ- mental samples are dependent on the quality of sampling methods used and the care taken in utilizing these methods. Of primary concern in both petroleum hydrocarbon baseline and oil spill samplings is the avoidance of sample contamination and cross contamination. R.C. Clark and Brown (1977) presented details of quality assurance aspects of collection techniques, which included attention to the cleanl iness of

96 sampl ing dear ices, subsampl ing implements, and star age conta iner s and the exclusion of field (shipboard) contaminants from the samples. Details of collection methods of seawater, sediments, biota, and waterborne oil samples were presented in R.C. Clark and Brown ~1977) , D.R. Green (1978), and ASTM Method D 3325-78. Sampling strategies have been developed for each spill scenar lo, and usually provide for pre- impact (baseline) and postimpact samplings, reference samplings (unimpacted sites), and a postspill time series to examine details of recovery (e.g., Boehm et al., 1981b; Atlas et al., 1981; Teal et al., 1978; Burns and Teal, 1979; Keizer et al., 1978) . Sediments Recent laboratory and f ield studies have revealed new, important subtleties related to sediment sampling, both in spill and nonspill situations. Gearing et al. (1980), in controlled experiments, and Boehm et al. (1981b) , in a field assessment, pointed to the importance of sampling newly deposited hydrocarbon-bearing sediment (i.e., floe) in oil spill studies. Thompson and Eglinton (1978b) showed that different particle sizes and types within a given sediment have differing hydrocarbon compositions. Determination of petroleum and PAR chemical composition associated with dif ferent types and sizes of sediment particles may yield important information on availability of certain compounds for biological uptake in benthic communities. A variety of sediment samplers has been used to obtain "surface sediment. These include box corers, which are most useful in soft bottoms and acquire a relatively undisturbed core of sediment; grab samplers (e.g., Smith-MacIntyre and Van Veen), which are useful in all sediment types, but may be subject to sample washout in gravelly or shelly sediment; gravity corers, which utilize a core liner (polyear- bonate) to obtain a cylindrical core of sediment which may be subdivided for analysis; hydrostatically damped corers in multiple arrays (Pamatmat, 1971; Wakeham and Carpenter, 19761, which have damped rates of sediment penetration; sediment boundary layer suspension (floe) collectors (Bryant et ale , 1980~; diver and other manual collectors (Atlas et al., 1981; D'Ozouville et al., 1979~. The selection of the sampling device is dictated by the sediment type being sampled and the informational needs of the particular program. Sediment Traps The design of sediment traps to ensure efficient collection and postcollection preservation of sedimenting material is an area of intense research and debate (e.g., Wakeham et al., 1980; W.D. Gardner, 1980; Jannasch et al. , 1980~. Traps have been utilized to examine the fluxes of suspended organics, including hydrocarbons, to open ocean and coastal sediments. The deployment of unsophisticated sediment traps in spill situations has provided critical information on the fate of

97 spilled oil (Boehm et al., 1981b; Johanssen et al., 1980; Boehm and F lest, 1980a) . Mar ine Organisms A var iety of sampling devices exists for the collection of pelagic and benthic marine organisms (R.C. Clark and Brown, 1977; Grice et al., 1972 ~ . These include plankton nets, trawls, and dredges of var. fed design (see Biological Methods section). Extreme care must be taken to avoid sample contamination from the sampling device, from the ship and ship's discharges, from the sample containers, and from oil in the water column. For example , collection of uncontaminated pelagic biota samples from a ship during a spill event is very difficult, and it is difficult to distinguish ingested from external oil (American Petroleum Institute, 19771. Diver collections are preferable in these cases. Again, the choice of sampling device and the sampling design depend on the nature of the organism and the program's statistical design. For example, in order to examine the relation of oil in the sediment to its bioaccumulation in benthic organisms, animal samples should ideally be obtained in close proximity to the sediment sample, with either divers in subtidal areas or manually in intertidal areas, and from the same sampling device (e.g., box corer). A n sample ~ of mar ine organisms for analyses is def ined by both analytical and statistical considerations. An estimated 1-10 g dry weight (100 g wet) are usually needed for prespill analysis and for spill-impacted samples to achieve analytical detection limits. However, the optimum sample size (i.e., number of organisms per sample) is dic- tated by several considerations, including whether information on a population at a certain station is required, or knowledge of individual- to-individual variation is desired (Boehm, 19781. Seawater Sampling of seawater to obtain information on hydrocarbon levels, in both baseline and spill-related samples, is the most difficult of samplings due to (1) the potential for contamination from the surface film (Gordon and Keizer, 19741, (2) the potential for contamination from the sampling device (Boehm and Fiest, 1978; Zsolnay, 1978a) or from associated rigging and the sampling ship or platform, and {3 possible problems with compar ing data from samples obtained with different sampling devices (Levy, 1979a; Boehm, 1980a). Use of the various available devices for obtaining seawater samples for petroleum hydrocarbon determinations has been reviewed recently by D.R. Green (19781. Examples of the problems encountered are contamina- tion by certain plastics and "O. rings. In addition, accumulator systems (e.g., octadecylsilicic reversed phase adsorbents [May et al., 1975; Eisenbeiss et al., 1978; Saner et al., 19791, XAD-2 macroreticular resins [Ehrhardt, 1978] , and polyurethane foam [e.g., deLappe et al., 19801) have been used with varying results to concentrate hydrocarbons

98 on solid phases. Alternatively, large volume water samples (10-90 L), which pass through the surface in a closed position, must be used to achieve analytical detection 1 imits which allow sub-part-per-billion ~ug/L) levels of hydrocarbons to be detected (e.g., deLappe et al. , 1980; Boehm, 1980a; Farrington et al., 1976a) . Chester et al. (1976) and Keizer et al. (1977) utilized simple devices to obtain 4-10 L of sample using glass bottles which manually open below the surface. Recently, pumping systems have been applied successfully to the subsur- face measurement of petroleum in the water column below surface oil slicks (Fiest and Boehm, 1981; Boehm and Fiest, 1980b; McAuliffe et al., 1980; J.C. Johnson et al., 19781. The use of discrete versus continuous sampling systems is dictated by the sampling scenario. Continuous pumping systems can be used for separation of dissolved and particulate water column samples (Ehrhardt, 1978; Goutz and Saliot, 1980; deLappe et al., 1980; Boehm and Fiest, 1980b), although water from discrete samplers can be pressure filtered through glass fiber filters (Boehm, 1980a; J.R. Payne et al., 1980a). Ehrhardt (1976, 1978) and deLappe et al. (1980) describe continuous seawater pumping systems which pass large volumes of water through in-line glass fiber filters upstream of XAD-2 resin and polyurethane foam. Dissolved and particulate size fractionations are important in discerning the fate and pathways of biological uptake of spilled oil (Zurcher and Thuer, 1978; Boehm and Fiest, 1980b) and distribution of petroleum hydrocarbons in seawater in nonspill studies (Goutz and Saliot, 1980; Boehm, 1980a). However, the terms "dissolved and ~particulate" are operational in nature due to possibilities of passage of colloidal-sized particles through the filter and the likelihood of changing the pore size of the filter as filtration proceeds. Sampling for Low-Molecular-Weight Hydrocarbons Samples (sediment, seawater, biota) to be analyzed for low-molecular- weight hydrocarbons require special handling. After collection, water samples should be treated to avoid agitation or inclusion of air bubbles in storage bottles. Water samples should fill sample bottles and be sealed with a Teflon cap, leaving no headspace, and be refrigerated until analysis proceeds (Brooks et al., 1980~. Sediment samples should also fill sampling containers and they should be frozen. Alternatively, sediments can be transferred immediately to containers holding "poisoned {e.g., sodium azide) hydrocarbon-free seawater, the container headspace flushed with helium or nitrogen and the container inverted at near-freezing temperature (Bernard et al., 19781. Biota samples should be frozen until subsampled for purgeable organics (Environmental Protection Agency, 19801. Sample Preservation There is a general lack of information on the longevity of petroleum hydrocarbons in stored, unextr acted samples of all types. Thus, the

99 procedures descr ibed are based, in most cases, on first principles, with r egard to minimiz ing processes that will alter the compounds of interest. All samples (sorbents, filters, sediments, tissues) should be frozen at -10 ° to -20°C after collection. Water samples, however, are impractical to freeze and can be solvent extracted aboard ship or preserved in the dark with a bacterial retardant (chloroform, methylene chloride, mercuric chloride, sodium aside). However, care should be exercised in the choice of preservation technique. Samples obtained for multiple use in chemical and biological studies should be preserved in a manner that does not mitigate against certain measurements; e.g., sodium aside would not be acceptable for samples to be used in a variety of biochemical or physiological studies. Volatilization of hydrocarbon components and microbial and photochemical oxidation of organic matter in samples are the primary concerns to be addressed in postsampling preservation. ASTM Method D 3325-78 presents a standard method for storing waterborne oil samples. The effects of long term (months to years) storage of samples under "preserved conditions is largely unknown, although Medeiros and Farrington (1974) determined that, after 18 months of storage of oil-spiked cod liver lipid extract, analytical results for some major hydrocarbons were unchanged. SP TLLED OIL CHARACTERI ZATIONS As the behavior and environmental fate of spilled oil are dependent on the physical and chemical properties of the oil and the meteorological/ oceanographic conditions, there is a need for full character ization of an authentic sample of the source of oil and a ser ies of oil samples from the water's surface and from oiled beaches. These oil samples will serve as reference materials for environmental analyses and also may be used in damage assessment studies and in judicial proceedings. In addition, rapid analytical information should be obtained during of Ashore spill scenar ios to predict the physical, chemical, and toxico- logical properties of oils after being waterborne and as they may impact sensitive shorelines. Offshore and shoreline countermeasure strategies often hinge on the knowledge of the physical properties of spilled oil, actual and predicted. Sample Collection and Preservation The original 1975 NRC collection guidelines should be adhered to and supplemented by ASTM Methods D 3325-78 and D 3694-78, U.S. Coast Guard ( 1977 ~ considerations of collection, sample documentation, and chain-of-custody procedures, and sample preservation. Several authentic cargo samples should be collected in all cases along with waterborne oil samples. Replication is important, as floating oil patches exhibit significant heterogeneity. If possible, floating oil patches or slicks should be marked with buoys and sampled periodically until dissipation or landfall . Samples should be taken

100 from small boats or helicopters, as it is often impractical for large ships to enter large oil patches. Cross-contamination should be avoided, especially while sampling in areas of heavy contamination wherein gear and clothing may become oiled. Gloves, protective clothing, and activated charcoal trap respirators should be used while working in heavy oil, and personnel should be monitored by a trained medical stat f . The samples should be taken in suf f icient quantities to permit replicate physical and chemical analyses. One hundred milliliters of sample are needed for some physical tests (e.g., viscosity), so wherever possible, liter-sized jars should be filled with sample. Sample documentation should be made on prespecif led, durable, water- proof tags (e.g., U.S. Coast Guard, 1977) to include information on collection location, date, time, name of collector, and sampling device. All collections should be logged in a master log and given a unique sample number . Consecutive number ing National Oceanic and Atmospher ic Administration, 1980 ~ us ing collector codes has proven extremely efficient in sample collection operations, and avoids ambiguous situations which occur during all collections when several people or groups are sampling concurrently. Preservation of oil samples involves the containment of low boiling components and the retardation of degradation through postsampling photochemical and microbial degradation. Analytical Methods Physical and chemical information should be obtained as soon as possible after the spill occurs. Field Information The existence, extent, and mapping of subsurface oil concentrations may be acquired during spill events through the use of in situ (towed) fluorometers (Environmental Devices Company, 1977; Calder et al., 1978) or continuous pumping through shipboard fluorometers (e.g., Boehm and Fiest, 1980b). Several important physical measurements, such as the determination of water content of oil {i.e., emulsification state) and the specific gravity of oil, can be made using simple devices (National Oceanic and Atmospheric Administration, 1977~. This information is valuable to countermeasure strategies (i.e., use of dispersants, application of booms, estimations of cleanup efficiency). Laboratory Information (Short Time Frame: Days to Weeks) Samples shipped to the laboratory should be subjected to a series of routine physical property tests to determine the oil's characteristics and behavior. These include accurate specific gravity, viscosity, pour point, and fractional distillation temperatures. ASTM procedures exist

101 for all of these measurements (R.C. Clark and Brown, 19771. In addi- tion, useful parameters associated with the emulsification process are the asphaltene and wax contents of whole oil. Ideally, chemical testing in the laboratory should include class separation to obtain information on the initial and changing relative proportions of saturated hydrocarbon, aromatic hydrocarbon, and polar and asphaltic fractions. Oils should initially be dissolved in methyl- ene chloride, or s imilar solvent with water r emoved by phase separ at ion and drying over sodium sulfate. The extract is then deasphalted by precipitation by pentane addition (ASTM Method D 893-80), and a portion of the pentane is charged to and elated on silica gel, silica gel/ alumina, or other column (see Measurements and Detailed Analysis of Environmental Samples section). A class separation and characterization sequence based on initial normal phase high pressure liquid chromatog- raphy (HPLC) (equivalent to silica gel column chromatography) followed by detailed capillary GC analysis (Gas Chromatography section) and analytical HPLC (High Pressure Liquid Chromatography section) has been described by Crowley et al. (19801. Laboratory-derived data should include GC analysis, preferably capillary GC, of the hydrocarbon fractions so as to determine the boiling range and overall composition of the oil. Laboratory Information {Long Time Frame: Weeks to Months) Techniques of petroleum character ization include those that der ive detailed compositional information as well as those that obtain information used to match waterborne oils with suspected cargoes through TR (infrared spectrometry), W/F (ultraviolet fluorescence spectrometry), GC (gas chromatography), FID (flame ionization detector) element specific detectors, and trace metal (Ni/V) measurements (U.S. Coast Guard, 1977; ASTM Methods D 3415-79, D 3414-79, D 3650-78, D 3328-78, D 3327-79) . Gas chromatography with f lame ionization and sulfur- or nitrogen- specif ic detectors yields considerable information on the molecular weight range of hydrocarbon components, and is one of the more powerful methods for broadly characterizing crude oils (Crowley et al., 1980; Rasmussen, 1976; Clark and Jurs, 1979) and refined products (e.g., Ury, 1981~. Graphical plots of the relative saturated and aromatic compo- sitions of oil samples (Patton et al., 1981; Atlas et al., 1981; Boehm and Fiest, 1980b) complement specific calculated parameter ratios in descr ibing the oil's chemical properties. IR measurements, in addition to having forensic use, can be used to characterize major compound groups and to evaluate weathering in a gross way by the appearance of carboxyl and hydroxyl functional groups (Rashid, 1974; Blumer et al., 1973; W.E. Reed, 19771. Mass spectrometr ic (MS) class and group (or subclass) analyses pro- v icing quantitative information on some 25 molecular types have proven very useful in compar ing oil types and in readily evaluating the chemi- cal character istics of fresh and weathered oils (Robinson and Cook, 1969; Petrakis et al., 1980; ASTM Method D 2786-71~.

102 GC/MS techniques have been used to identify fresh and weathered oils based on detailed compositions (Hood and Er ickson, 1980; Albaiges and Albrecht, 1979; Atlas et al., 1981; W.E. Reed, 1977; Calder et al., 1978; Overton et al., 1980b; DeLeon et al., 1980; Schmitter et al., 1981) . HPLC is another technique for character iz ing oils on the teas is of their aromatic hydrocarbon content (e.g ., Crowley et al ., 1980 ~ . A combination of IR and HPLC analyses, to quantify and characterize saturated and aromatic petroleum hydrocarbons, respectively, has been used in conjunction with Go for analysis (Riley and Bean, 19791. Further long-time-frame characterizations of spilled oils include the techniques of carbon and sulfur isotope ratios (Koons et al., 1971; Hartman and Hammond, 1981; Sweeney et al., 1980), proton and 13C nuclear magnetic resonance spectroscopy {Petrakis et al., 1980), and elemental (C, H. N. S) analysis (e.g., W.E. Reed, 1977; National Research Council, 1975~. Additionally, many of the analytical techniques used by petroleum chemists may effect more detailed char- acterizations (Terrell, 1981~. Examples of detailed multiple-technique characterizations of oils are given by W.E. Reed (1977) for weathered tars, W.E. Reed and Kaplan (1977) for marine petroleum seeps, and Overton et al. (1980b) for Ixtoc I oil. MEASUREMENTS AND DETAILED ANALYSIS OF ENVIRONMENTAL SAMPLES Gener al The analysis of a particular sample of water, sediment, tissue, air, etc., for petroleum hydrocarbons must be preceded by matching the particular informational need with the proper analytical technique. For example, information may be needed on the gross amount of oil in the dosing system of a toxicological study or on concentrations of an individual aromatic toxicant (e.g., naphthalene) and its metabolites (e.g., naphthol) in a marine fish. Single analytical techniques (e.g., W , GC) can be used for certain applications when the analyt ical end is to examine absolute levels or compound assemblages (nonpoint sources), but multiple techniques (e.g., W + GC ~ IR) are required for forensic purposes in matching environ- mental compositions of petroleum to specific point sources. Figure 3-1 illustrates various analytical options for environmental samples. The proper choices of separation and analytical techniques are at the heart of environmental petroleum hydrocarbon chemistry. In general, the less chemically specif ic techniques require less sample processing and manipulation. With increased processing, the level of analytical detail, and hence compositional and quantitative information, increases. The field of oil pollution chemistry has expanded rapidly in the past 5-10 years without great attention to intercomparabil ity of measurements between different laboratories using similar techniques and between different analytical techniques used to generate data. The generation of analytical data continues at a rapid pace at different

103 SAMPLE 1.) PRETREaTMENT (DRYING, IdOMOGENIZATION, e I l 2.) EXTRACT WITH SOLVENTS SUBSAMPLE FOR VOLAT I LE HY DROCARBON S GAS STR I PP I NG GAS EQUI LlBRiUM Dl RECT I NJ ECT I ON PU RG E AN D TRAP G C , ~ H IGH L IPI D SAMPLES 1.) SAPON I f I CAT I ON 2.) aLUMINA PRE COLUMN SAPONIFIED LIPI DS - T OT A L NON - SAPON ~ f I ABLE ORGAN I CS 1 F3 POLAR FRACT I ON S TLC HPLC GC2/MS | SATURATES | r ~ ~, STRA I G HT BR~ ~E D 2 ~! ~ CY~Ll C GC ~Gr 2 le. ) ~, ~ . | TOTAL EXTRAC~L_~= GRAViMETRIC (Oil ~ Grease) ORGAbJ I C S - ~ UV/ F LOW LIPIt) SAMPLES POLAR ITY SE PARATIO \IS 1.) COLUMN OR TH IN LAYER CHROMATOGRAPHY ( Florisil, Silica Gel, Clay) . ~ HYDROCARBON FRACT IONS - GRAVIMETRY _ - GC2 - GC 2/~s ~IZE SEPARATION | | MOLECULAR SIEVES | ARO MAT~ OLEF I NS . . GRAV I M ET R Y I R UV / F GC2 GC2/i'S S I ZE SEPARATION - GEL PERMEATION - CHROMATOGRAPHY , HPLC or SEPHAC)E X) ( | OLEFINS 1 | AROMGTICS | 1 F21 1 GC2 GC2/MS FIGURE 3-1 Analytical options for analysis of petroleum compounds in sediment, tissue, particulate matter, and water. levels of sophistication. Recently the ACS Subcommittee on Environ- mental Analytical Chemistry published its "Guidelines on Data Acqui sition and Data Quality Evaluation,~ which expressed three interwoven strategies of modern trace analysis: (1) the development of sensitive, specific, and validated methods; {2) the use of protocols that describe

104 the details of the measurement process and sampling procedures; and (3) the use of quality assurance procedures to monitor the quality of the data as it is developed. At the heart of all data generation should be procedures of rigorous quality assurance including routine determina- tions of procedural blanks, instrument calibration and standardization, analytical precision on replicates, recovery of spikes, detection limits, and comparison of results with other laboratories (intercalibra- tions) {MacDougall and Crummett, 1980~. These guidelines should become part of all petroleum hydrocarbon studies. In addition, the precision of environmental analytical measurements has three components: (1) instrumental variation (replicate analyses of the same solution), (2) analytical variability (analysis of replicates of the same homogenate, or subsamples), and (3) sampling variability (replicate analyses of sampling replicates). Numerous methodologies have been used in conjunction with oil pollution studies, and the efficacy of the various methods used, for example, in extracting and fractionating organic matter from sediment and in performing detailed analysis of hydrocarbons, has only recently (since 1975) come under rigorous study through both intralaboratory experiments and thorough intercalibration exercises. Extraction of Organic Matter (High Molecular Weight, Cll+) Hydrocarbons Sediments Several different solvent extraction methods are commonly used for the extraction of petroleum hydrocarbons from sediments. No standard method exists, but most methods involve the combined use of polar and nonpolar solvents to effect an efficient extraction of organic matter. Geochemical and oil spill sediment samples differ in the ease of extraction of hydrocarbons from the sediment matrix, the latter containing loosely bound petroleum hydrocarbons. Thus while one of the rigorous extraction procedures is necessary to extract, for example, low to moderate levels (less than 10 ug/g) of PAH from a s~lt/clay sediment, simpler techniques may suffice for spill samples. As it is often important to discern levels of incremental addition of low to moderate levels of oil to sediments containing some prior history of anthropogenic pollution, the rigorous solvent extraction methods (e.g., Soxhlet, tumbler/shaker) are most appropriate for all environmental samples. Sediment extraction techniques include organic _ solvent extractions (e.g., D.W. Brown et al., 19801, alkali digestions followed by solvent extractions (Environmental Protection Agency, 1980; Farrington and Tripp, 1975), headspace gas stripping (May et al. , 1975) , and steam distillation (veith and Kiwas, 1977; Bellar et al., 1980) . Solvent extractions employ (1) the use of the Soxhlet extractor with a com bination of polar and nonpolar solvents (e.g., Hites et al. , 1980; Farrington and Tripp, 1975; Lake et al ., 1980 ; Environmental Protection Agency, 1980), (2) the reflux of sediment with organic solvents (e.g.,

105 Lake et al ., 1980 ), or (3 ~ ambient temperature extractions using the shaker table or ball mill tumbler (D.W. Brown et al., 1979, 1980; Boehm et al., 1981a). Van Vleet and Quinn (1978) utilized a methanol: toluene reflux of wet sediment to remove "unbound" lipoidal material followed by combined alkaline digestion solvent extraction to remove additional "bound" mater ial . Farr ing ton and Quinn ( 1973 ~ and Boehm and Quinn (1978) employed simultaneous saponification/extraction using a methanolic KOH: toluene reflux to remove hydrocarbons from sediment. In headspace analysis, Wise et al. (1978) and May et al. (1975) combined dynamic headspace sampling of hydrocarbons volatilized at 70°C for 18 hours with a coupled-column reversed phase enrichment step to recover volatile compounds up to 4- and 5-ringed aromatic compounds. The volatilized hydrocarbons were trapped onto a Tenax GC trap, which was then desorbed directly onto a capillary GC column. Tan (1979) utilized ultrasonic solvent extraction using cyclohexane of freeze-dried sediment to reproducibly extract PAH material. A very rapid extraction technique using a process called "flow blending" utilizes solvent extraction of mater ial in a f low-through cell (Radke et al ., 1978 ~ . Using this technique, extraction eff iciencies comparable to Soxhlet extraction were achieved for a wide range of sample types. While several of the recently published methods included the use of benzene (Boehm and Quinn, 1978; Lake et al., 1980), this solvent is now restricted from use in the laboratory due to health effects. Methylene chloride and toluene have replaced benzene as solvents of intermediate polarity, having good extraction efficiency alone or in azeotropic mixture with other solvents. Comparisons of several of these extraction techniques have been reported by Farrington and Tripp (1975), Rohrbach and Reed (1976), Lake et al. (1980), D.W. Brown et al. (1980), Bellar et al. (1980), M.K. Wong and Williams (1980), and Templeton and Chasteen (1980~. Present evidence suggests that Soxhlet and tumbler or shaker techniques are the most thorough extraction procedures and are most widely used. Use of different extraction techniques by different laboratories can yield comparable analytical results for individual n-alkanes and PAH at 0.01-to 1 ug/g concentrations in sediments (MacLeod et al., 1981a). The ambient temperature tumbler method descr ibed by D.W. Brown et al. (1980 ~ allows for processing of large numbers of samples without the use of the expensive glassware, boiling solvents, hood space, and running water required by the Soxhlet extraction method. Tissues Petroleum hydrocarbons present in marine plants and animals include both those loosely bound to the tissue matrix and those occurring intracellularly. Several methods have been utilized extensively to extract these compounds. High natural lipid contents of many organisms present unique problems of extr act ion and analysis. Wet t issues can be extracted after homogenization by alkali digestion/saponification using aqueous or alcoholic KOH followed by addition of water or saturated NaC1 and partitioning into ethyl ether, pentane, hexane or isooctane

106 (Warner, 1976; Dunn, 1976; Pancirov and Brown, 1981) . Wet tissue may be f reeze dr fed and the dr fed t issue extracted us ing methanol followed by a nonpolar solvent (e.g. , hexane, benzene, methylene chloride) in a Soxhlet apparatus (Farrington et al., 1976a; Ehrhardt and Heinemann, 1975~. Simultaneous high speed homogenization/extraction using anhy- drous sodium sulfate and nonpolar solvent in a high speed homogenization apparatus can be utilized, followed by phase separation of the organic layer (Gay et al., 1980; Farrington and Medeiros, 19771. Alternatively, high speed homogenization/extraction using acetonitrile has been used in conjunction with pH adjustments followed by hexane extraction to obtain both hydrocarbon and other organic pollutants compr ising the Environmental Protection Agency ( 1980 ~ "pr for ity pollutant" compounds, which include PAH compounds. Steam distillation of tissue homogenates to obtain an organic extract (Ackman and Noble, 1973; Veith and Kiwas, 1977 ; Boehm et a] ., 1983 ~ is an attractive technique in that the extraction procedure is simplified and many polar lipid interferences are removed at the time of extraction. Lawler et al . (1978 ~ descr ibed a solvent reflux technique using hexane followed by benzene for extracting mallard tissues . R.C . Clark and Brown (1977 ~ presented a f ur ther d iscuss ion on t ~ ssue extr act ion methodolog ies . Farrington and ~Iedeiros (1977) and Gritz and Shaw (1977) have com- pared several of the more commonly used techniques--alkal ine digestion/ extr act ion, Soxhlet extr act ion, and h igh speed homogen izat ion extraction--and found the alkal ine digestion/extraction methods to be the most eff icient. However, absolute recovery data on all of the t issue methods are generally lack ing . The organic extracts from any of the tissue procedures, even those involving direct saponif ication ~ i .e ., alkaline digestion), contain inter fer ing polar 1 ipids and biogenic hydrocarbons along with petroleum hydrocarbons . Fur ther saponif ication of tissue extracts fac il. itates subsequent separation and isolation techniques (Farr ington et al., 1976a; National Research Council, 1975} . Extraction of alkaline digestates with nonpolar solvent usually results in gel formations which probably are compr ised of 1 ipoproteins. These compounds may be removed by use of an alumina precolumn (Warner, 1976 ~ or gel permeation chromatography (see Size Fractionation section). Seawater The prec ise choice of extraction techniques used to isolate petroleum hydrocarbons from seawater depends on the nature of the sampling de~rice used ~ see Sampl ing and Sample Preservation section) and the analytical method to be employed. The extraction methods used depend on whether a water sample must be extrac~ed or whether the organics in the water have been previously sorbed to an accumulator resin (e.g., XAD, poly- urethane, reversed phase columns) . Boehm (1980a) extracted a large volume (90 L) of filtered seawater in a continuous stainle~;s steel 1 iqu id-1 iquid extractor for 6 hours and the corresponding glass f iber filter in sequential methylene chloride and hexane solvent reflux. R.A. Brown et al. (1975) and R.A. Brown and Huffman (1976) used batch - .

107 (separatory funnel) carbon tetrachloride extractions of unfiltered 3- to 5-L samples to isolate petroleum hydrocarbons. Boehm's analytical goal was detailed GC and GC/MS analyses; the latter investigators were making infrared measurements of total hydrocarbons. Gordon et al. (1978) made batch extractions of 36 L of unfiltered seawater with doubly distilled pen tane for subsequent W/F and GC analyses. Clearly, the solvent employed must suit the analytical method. In all cases, scrupulous attention to solvent and reagent purities and blanks is required due to low levels expected (0.1-10 ug/L) (Boehm, 1980a; R.A. Brown et al., 1975~. ASTM Method D 3326-78 describes standard practices for the extrac- tion of high levels of waterborne oil, including chloroform or methylene chloride extraction and centr if ugation. The use of accumulator columns (e.g., macrorecticular resins) to isolate hydrocarbons from seawater is becoming increasingly important, although definitive data on sorption and resorption efficiencies are generally not available for these promising techniques. Extraction of the absorbent is performed using a combination of polar and nonpolar boiling solvents either by direct column elusion (Bean et al., 1980; Harvey and Giam, 1976) or in a Soxhlet extractor (Basu and Saxena, 1978~. Reversed phase HPLC precolumns (e.g., Clg Bondapak) have been used to adsorb hydrocarbons from seawater, with the resulting column then being coupled to an analytical column and elated into a liquid chromatograph for analysis (e.g., May et al., 1975; Ogan et al., 1979; Saner et al., 1979~. Concentration of Extract Analysts must exercise caution when concentrating solvent extracts to small volume on dryness to avoid excessive loss of compounds in the extract. This is especially a problem for compounds in the Clo-C13 molecular weight range, and most analysts report data for compounds of molecular weight C14 or Cls and greater. Sample Cleanup and Fractionation In order to increase the precision and discrimination of all analytical techniques, samples may be treated by any one or a series of several types of sample cleanup and fractionation techniques which fall into three basic categories: polarity, size, and chemical separations. These techniques separate petroleum hydrocarbons from lipoidal material, fractionate the hydrocarbons into one or several parts to facilitate analysis, and can isolate nonhydrocar bon components (e.g., azaarenes, phenols) from the petroleum hydrocarbons. The application of one or more separation techniques depends both on the nature of the sample (i.e., amount of polar material) and on the focus of the analysis. Several illustrative sequences are shown in Figure 3-2.

108 ~ _ Z~ ~r c_' X 'c~ o^~= :] 1 [ .~ ~o;~ ~- ~ '~ ~ ~ ' ° 3-~ o ~' ,~ ~ _ C ~ ~, ., ° o ° 'U. ~ ° ._ o _ ,o - o c _ Q C' ' CP O O .o O . _ C cn o C C _ O _ > o C o ~ ·_ CI X ~ ~ ~ . ~ O O L) O O ¢} · C ~ Z° = -C" _ 0 =0 {,) _ _ ._ O O U. ~ ~C _ _ _ `0 q) I,~ C e: ~ ~] 1 H 1 ~ -1 r I ~)._ ~r . ~ , > 1 o 1 o 1 ' ~ 1 ~ 1 CJ 1 1 1 ~ ~o I o ~ 1- ~ ~ Cl ~1 ~1 \1 ~' ~ I ~ 1 / ~ I 1 1 1~ 1 1 z L~ "o 0m /~ ~ " ~ {=~ 1 ~ 1 c _ 1 o co _ 1 ~ ~, 1 ~ - O 1 o c ,l) co 1'~ o 0 I `~ m ~ ._ ct) _ C' ~ r~ 1 ~ c, 1 ° ' ao 1, `_ 1 Q) C' 1 ~ ~ ~ I ._ C~ 1 ~ cr) C' / - o) 0 0 J c:s - ~ o o h_ ~cn ._ l1 - a, o - > o ~e o 0 cn ~e 3 e~ Sv o a~ tOe o ~e 4 o S ~4 - o JJ P. ee~ ~q Q. C~ 1 ~r; e~)

109 Polar ity Fractionation Suggested references to some recent applications of polar ity fractiona- tion techniques are ASTM Methods D 2007-80 and D 2549-76, Warner (1976, 1978 ), Giger and Blumer ~ 1974 ), MacLeod et al . (1981b), Environmental Protection Agency (1980 ), J.N. Gear ing et al . (1978), Daisey and Leyko (1979), and Over ton et al. (1980a,b). S. ize Fr act donation Suggested references to more recent applications of size fractionation techniques are Albaugh and Talar loo (1972), Ramos and Prohaska (1981), Giger and Schaffner {1978 ), Warner et al . (1980 ), Overton et al . (1980b), Pym et al. (1975), Dastillung and Albrecht (1976), McTaggart and Luke (1978), and Albaiges ar~d Albrecht (19791. Chemical Techniques Sample extracts containing high concentrations of lipoidal material ~i.e., sediments of high organic content, and tissues) are often saponif fed (Farr ington et al ., 1976a) pr for to any fractionation or analytical steps to conver t solvent soluble waxes and glycer ides to their fatty acid salts and alcohols. The polar lipids can then be partitioned into water, leaving a less complex extract containing nonsaponifiable lipids, which include the petroleum hydrocarbons. Saponif ication does , however, preclude the analysis of some compounds such as the family of DDT pesticides, as the alkaline hydrolysis converts DDT and DDD to DDE. A variety of separation techniques based on chemical interactions of petroleum hydrocarbon and nonhydrocarbon molecules with resins, complexing agents, and solvents has been used alone or, more commonly, in conjunction with other procedures to achieve postextraction fractionations to facilitate analyses. For example, removal of elemental sulfur from sediment extracts by reaction with activated copper prior to analysis (Blumer, 1957) is accomplished either on the total sample extract or on the aromatic silica gel fraction. The presence of elemental sulfur greatly interferes with mass spectral determinations, and removal from sediment extracts prior to analysis is recommended. Dimethyl sulfoxide (DMSO) has been used to partition PAH compounds selectively from sample extracts (Dunn and Stich, 1976; Natusch and Tomk ins, 1978 ~ . Other chemical techniques have been used to isolate nonhydrocar bon components of petroleum and petroleum- containing samples. Basic nitrogen heterocyclics in an organic extract may be partitioned into an aqueous acidic extract (Jewel!, 1980 ~ . Oxidation and reduction (LiAlH4 ~ reactions have been used to facilitate the isolation of nitrogen and sulfur heterocyclics (Jewel!, 1980; Willey et al., 1981~. Pentane-soluble nonhydrocarbons such as pyr idines, phenols, carbazoles, and amides can be isolated from nonpolar hydrocarbons by means of their chemical reaction in ion

110 exchange resins or transition metal salts (Petrakis et al., 1980~. Aromatic hydrocarbons can be isolated from sample extracts via charge transfer complexation reactions (Giger and Blumer, 1974) in conjunction with polarity and/or size separations. Analytical Methods for Cll+ Hydrocarbons (Nonvolatiles) A variety of analytical methods is available to analyze the levels and composition of hydrocarbons in the solvent extract of an environmental sample. Since the mid- to late-1960s, investigators have realized that techniques to measure petroleum hydrocarbons (PHC) in the marine environment must differentiate incremental additions of newly spilled oil from background levels, both from a quantitative and a qualitative view. Such techniques must adequately measure the concentrations of PHC at levels 10 times or more lower than the traditional "oil and grease. (Environmental Protection Agency, 1979) measurement, and techniques must be available to resolve and quantify individual petroleum components at concentrations less than biogenic hydrocarbon concentrations. Techniques are now available that make the nonspecific oil and grease measurement and then fractionate the extract into one or more PHC fractions analyzable by different methods. The range of measurements go from (1) nondiagnostic gravimetric measurements, to (2) the gross concentration measurements of TR, W absorption, W/F spectrometry (with some diagnostic power, albeit concentrations are based on "oil equivalents" and thus are not "absolute concentrations I, to (3} the middle to high resolution techniques of high performance (pressure) liquid chromatography, glass capillary gas chromatography (GC2) and computer-assisted glass capillary gas chromatography/mass spectrometry (GC2/MS). These techniques and several others encompass the methods available to arrive at petroleum hydrocarbon data. They are often used in a hierarchical manner where "screening" is followed by detailed analyses (e.g., Figure 3-3 Gravimetr ic Methods If sufficient material is available from the extraction processes, an aliquot of the extract may be weighed, using an electrobalance, by evaporating the solvent on the weighing pan and weighing the residue. As 1 ittle as 5 ug of mater ial can be weighed. Gravimetry and microgravimetry have been applied to gross determina- tions of both total extractable material, i.e., oil and grease (Environ- mental Protection Agency, 1979; ASTM Method D 2778-70; Eganhouse and Kaplan, 1981), and of levels of petroleum hydrocarbons (Farrington et al., 1976a). The former determination does not differentiate the hydrocarbon from the nonhydrocarbon material in a given sample, thus lumping together hydrocarbons and the more abundant nonhydrocarbon lipoidal material. The oil and grease measurement may yield useful information vis-a-vis petroleum-related contamination in samples in which the hydrocarbons are far more abundant than background lipophilic

111 ::: - | SAMPLE CLEANUP | - 1 1- 1 1 1 EXTRACT ION U V / f LUORESCENCE ~ Sl LIC IC ACID CO LUM N CH ROM ATOGRA P HY fRACTION 1 FRACTION 2 SATURATES AROMATI CS 1 ~ Get _ _ _ / / / ~- -DETAILED COMPOSITIONAL INFORMATION -QUANTITIES OF INDIVIDUAL MINOR PAH, HOPA N ES, AZAAREN ES - MAXIMUM CHEMICAL INfORMATION -RELATIVELY HIGH EXPENSE 1 ' -OIL? YES OR NO -APPROX IMaTE QUANTIT I ES -INEXPENSIVE AC I D I C EXTRACT ION AZAARENES / r - DETAI LED RESOLUT ION OF COMPLEX M IXTURES -QUANTITATIVE FOR MAJOR COMPON E N TS -SOU RCE I DENTI Fl CAT ION FINGERPRINTING -MODE RATE EXPE NS E FIGURE 3-3 Hierarchical scheme for analyses of petroleum hydrocarbon in environmental samples. material (e.g., oil spills), in which levels of hydrocarbons are greater than the method' s detection limit (~10-50 ug/L in a 1-L sample, using an electrobalance; minimum absolute weight determination of 5 ug), and in which more detailed compositional information is also obtained. Infrared Spectrometry Infrared spectrometry is well suited as an analytical technique for the identif ication of waterborne oil and match i ng with suspected cargos of crudes and fuel oils ~ i . e ., f ingerpr inting) . Identif ications are based

112 on compar isons of the intensities of spectral bands in an unknown with those of suspect cargos over the entire spectrum, or using specific bands (ASTM Method D 3414-79; U.S. Coast Guard, 1977; Bentz, 1980; J.W. Anderson et al., 1980~. As a quantitative technique, IR has been used to monitor concentra- tions of oil in laboratory dosing of seawater systems through calibra- tion and measurement of sample extract IR absorbance at 2,290-2,930 cm~1 (-CH2-stretch) (e.g., Rice et al., 19761. Concentrations of oil in environmental samples have been determined using similar IR measurements on CC14 extracts of sediments following the Santa Barbara blowout (Kolpack et al., 1971) and the Amoco Cadiz spill (}qarchand and Caprais, 1981~. However, application of quantitative IR measurement to sediment samples is only suited to s ituations in which large amounts of oil (>1 ug/g) are present above background levels due to the method' s inability to (1) distinguish fresh oil from background (chronic) pollu- tion in coastal sediments, and (2) distinguish petroleum from biogenic material. Furthermore, if samples are not subjected to a fractionation step separating hydrocarbons from those polar lipids prevalent in all samples, then the method is totally inadequate to distinguish small amounts of hydrocarbons in the presence of much larger quantities of lipids, both of which contain -CH2 bonds. Furthermore, measurement of the -CH2-stretch yields measurements of only saturated molecular systems, giving no information on aromatics and not taking into account postspill differential chemical weathering of the source oil. Riley and Bean (1979) used IR in conjunction with HPLC (see High Pressure Liquid Chromatography section) to monitor sedimentary PHC for saturated and aromatic hydrocarbons. R.A. Brown and Huffman {1976, 1979), R.A. Brown et al. (1975), Gruenfeld (1975), and Gruenfeld and Frederick (1977) have used IR measurements to determine concentrations of hydrocarbons in seawater after performing a silica gel separation of hydrocarbons from "total extractable organics. n These measurements are better suited than the oil and grease (i.e., unfractionated) IR data, but in nonspill situa- tions they still suffer greatly from difficulties of interpretation and accurate quantification of petroleum hydrocarbons. IR analysis has been used for qualitative assessments of hydro- carbon oxidation through measurement of the C = Stretch (e.g., Rashid, 1974; Wade et al., 1976; Blumer et al., 1973) and for the quick screen- ing of the efficacy of nonpolar/polar compound separation techniq~aes (see Sample Cleanup and Fractionation section). Ultraviolet-Visible Fluorescence (W/F) Spectrometry Also known as spectrofluorometry, this method has achieved widespread use for the determination of background levels of petroleum hydrocarbons in seawater (Levy, 1971, 1980; Keizer and Gordon, 1973; Law, 1981), sediments (Boehm and Fiest, 1980c; Wakeham, 1977), and tissues (Fong, 1976; Zitko, 1975), and in oil spill sampling as well (e.g., Eaton and zitko, 1979; Law, 1978; ~qackie et al., 1978; Fiest and Boehm, 1981~. W/F has been used in conjunction with other analytical techniques to

113 match waterborne oil with suspected cargo in forensic studies (Bentz, 1980 ~ . W/F spectrometry or spectrof luorometry involves both the ultraviolet (200-400 nm) and visible (350-600 nm) regions of the electromagnetic spectra. Fluorescence procedures are geared to the determination of aromatic hydrocarbon molecular structures, although other conjugated molecules (e.g., polyolefinic compounds) and hetero- cyclic aromatics will fluoresce. W/F spectrometry offers advantages of greater sensitivity and selectivity for aromatic molecules than the W absorption techniques (Farrington et al., 1976a). The fluorescence spectra of crude oils and petroleum products have been under intense investigation in recent years (John and Soutar, 1976; ASTM Method D 3650-78; U.S. Coast Guard, 1977; Eastwood et al., 1978; Eastwood, 1981) as the diversity of the aromatic compositions of crude and refined oils has resulted in "finger- printable. spectral characteristics. Excitation, emission, and synchronous modes of fluorometry have all been utilized for these studies, but the latter two are of greatest interest. Emission spectrofluorometry involves a fixed-sample excitation wavelength and a scan of emission wavelengths. The W/F of complex mixtures is provided with greater resolution by use of synchronous scanning (Lloyd , 1971 ; Vo-Oinh , 1978 ; Gordon et al ., 1976; Hargrave and Phillips, 1975; Keizer et al., 1977; Talmi et al., 1978), and both cryogenic low temperature (Shpol 'skii) luminescence (Fortier and Eastwood, 1978; Colmsjo and Ostman, 1980) and "total luminescence" methods (Hornig, 1974) have great potential for further spectral detail. The various possible scan modes are illustrated in Figure 3-4 (Giering and Hornig, 1977~. Although a rather simple technique, room temperature W/F is subject to severe errors and limitations, only some of which may be eliminated by attention to matters of calibration and matrix interferences. The keys to all of the quantification methods are (1) choice of the proper standard and {2) measurement in the dilution range where self-absorption and quenching effects are minimal. Ideally, the standard should be identical in molecular composition to the samples, but most often in nonspill scenarios the sourcets) of contamination is unknown. In spill situations the most appropriate standard is, of cour se, the spilled oil itself. However, composition changes rapidly due to weathering upon addition of oil to the marine environment. In nonspill cases, measure- ments of "equivalent oil concentrations" (i.e., crude oil equivalents) result, which do not necessarily agree with other, more accurate quantification methods, e.g., GC (Keizer et al. , 1977; Zsolnay, 1978b; Hoffman et al., 19791. In monitor ing subsur face concentrations of oil from an of fshore blowout using synchronous W/F, Fiest and Boehm (1981) encountered two entirely different spectral types (Figure 3-5), one similar to IXtoc oil and the other to its water-soluble fraction. The authors used gravimetric measurements of oil-in-water samples to correct equivalent oil concentrations to absolute levels for the two spectral types. Thus, if the source of the hydrocarbons is known, the ease and speed of the technique make it quite useful for "hot spot" determinations and environmental monitoring (e.g., Eaton and Zitko, 1979; Law, 1978;

114 A 700 - 200 _ 700 FIGURE 3-4 200 1 200 W/F scan modes. A EM/SS/O//{nmJ SOURCE: Adapted from Giering and Hornig (1977). ~ UO ~ E SC:~ B o IS LIZ X m Am IS o NORMAL FLUORESCENCE SCAN 700 Mackie et al., 1978), with the caveat that accuracy and more detailed compositional information are sacrificed. Baseline seawater measurements generally achieve estimated concentrations in crude oil equivalents (Levy and ~offatt, 1975; Law, 1981~. These relative measurements are of some value in examining temporal and spatial trends if quantifying methodology is consistent (e.g., International Oceanic Commission/World Meteorological Organization, 1981~.

- 115 1: TYPE B SPECTRUM tWater Soluble Fraction of Oil} 250 rim 300 350 400 450 500 nm 1 1 1 1 1 , , 1 ~, 1 1 Ring 2 Rings 3,4 Rings 5 Rings 1 ~ \ / J.\. TYPE D SPECTRUM (Whole Oil) / l \ I J 400 I , I I I I L I Ring 2 Rings 3,4 Rings - 450 250 nm 300 350 5 Rings FIGURE 3-5 Representative synchronous fluorescence spectra of water samples collected near the Ixtoc I blowout. 500 rim

116 The use of W/F as a screening technique for establ ish ing an incremental addition of oil to sediment and tissue samples has yet to be adequately tested. However, interference from compounds indigenous to the samples is anticipated to be more severe than for seawater extracts. As a f ield spill assessment technique, continuous fluorometric analyses of water pumped through an underwater towed system, using fixed excitation and emission wavelengths, has proven quite useful in real-time measurements of relative quantities of oil in the water column during spill events (Carder et al. , 1978; Calder and Boehm, 1981; Turner, 1979; Environmental Devices Company, 1977), especially in conjunction with other measurements such as acoustical reflection (Boehm and Fiest, 1980b). Thin Layer Chromatography (TLC) In addition to its use as a separation/fractionation tool (see Sample Cleanup and Fractionation section), TLC has been used as an analytical tool for both the rapid qualitative detection of the presence of oil in sediment samples (L.R. Brown et al., 1975) and the identification of spilled oil (U.S. Coast Guard, 19771. There is an extensive literature on the separation of aromatic hydrocarbons by TLC, followed by measurements directly on the plate or after spot elusion (Dunn and Young, 1976; Hunter, 1975; DiSalvo et al., 1975~. Recently, TLC techniques have been used in conjunction with studies of aromatic hydrocarbon metabolism (Gruger et al., 1981; Varanasi and Gmur, 1981b; Malins et al., 1979) to determine the identity of polar metabolites in fish. Two-dimensional TLC, using two-solvent systems (hexane:diethyl ether, 95:5; and toluene: ethanol, 9:1), was used in conjunction with measurements of radioactivity of (labeled) compound metabolites to determine the identity and concentration of specific metabolites (Varanasi and Gmur, 1981b). High Pressure Liquid Chromatography (HPLC) HPLC techniques have advanced rapidly in the past 5 years. Although not even discussed in the 1975 NRC report, HPLC is now a major emerging method for the analysis of aromatic hydrocarbons, labile metabolites, and petroleum-derived nitrogen bases in marine samples in many cases (Colin et al., 1981; Wakeham et al., 1981; R.F. Lee et al., 1978, 1981a; Warner et al., 1980; Dunn and Armour, 1980; Malins et al., 1979; Chmielowiec and George, 1980; Ogan et al., 1978; Wise et al., 1977, 1980~. As the technique involves nondestructive detection, HPLC may be used as a preparative mode and the column eluates saved (Wakeham et al., 1981), or in analytical mode using f ixed and var. iable wavelength ultraviolet absorption, or fluorescence detectors singularly or in series (T.R. Smith and Strickler, 1980; Christensen and ~ay, 1978; Das and Thomas, 19783. Refractive index detectors may also be used to measure nonfluorescent comp.ounds at high concentrations (Riley and

117 Bean, 1979~. Microparticulate columns can be used in the normal mode using silica columns (Wakeham et al., 1981), or in the reversed phase mode, wherein columns are packed with silica whose surface is coated w ith a chemically bonded phase ~ e . g ., bonded octadecyl s ilane columns ; Dunn and Armour, 1980~. HPLC elusion solvent systems range from single mixed solvent systems (e.g., water/methanol) to quaternary systems consisting of two pairs of mixed solvents which are aqueous and nonaqueous binary mixtures (T.R. Smith and Strickler, 1980), and which are run with progressively increasing amounts of the nonpolar solvent mixture (i.e., gradient elusion). HPLC offers major advantages in the analysis of thermally labile or nonvolatile polar compounds (i.e., metabolites; Krahn et al. , 1980, 1981) and high-molecular-weight parent PAH {greater than 6 r ings; Peaden et al ., 1980 ~ . There are limitations for analyses of both these groups of compounds when us ing h igh r evolution GC and GC/IlS analytical techniques. HPLC is well suited in analyses where nondestructive tech- niques are required. However, its use suffers from several disadvan- tages. Fluorescence and W absorption detection vary widely from compound to compound, and response factors change as wavelength settings are altered. Thus, a calibration curve of each compound must be determined. Consequently, the quantities of unknown compounds, or compounds for which standards are unavailable, can only be approximated. Additionally, partial fluorescence quenching may occur from interfer- ences in the sample, and complex environmental samples may contain inter ferences due to nonhydrocar bon f fluorescence or absorption. HPLC shows promise for determining the degree of PAH alkylation in petroleum-contaminated samples . Presently, confused chromatograms often result, wherein alkylated PAH of a given ring size may coelute with the parent PAH of the next larger ring size, thus making HPLC more suited as an analytical tool for combustion-related rather than petroleum-derived aromatics (see Chapter 11. Preparative HPLC using aminosilane packing can be used to collect fractions based on ring size, which can then be analyzed by reversed phase columns to determine degrees of alkylation {Bartle et al., 1981; Wise et al., 1977, 1980; Chmielowiec and George, 1980; Hertz et al., 1980; Ber thou et al., 1981) . Thus, while GC2 and GC2/MS techniques are still preferable in terms of their resolving power, recent HPLC techniques have increased their applicability to environmental petroleum and PAH analyses. Advances in HPLC detector s and coupl ing HPLC with MS-computer systems offer great promise for future uses in petroleum pollution research and monitoring. Intercomparison of HPLC- and GC2-derived data is an important prior ity for future intercalibration studies. Hertz et al. (1980) have provided an initial intercomparison study of GC, GC/MS, and HPLC analyses of PAH in shale oil. Gas Chromatography (GC ~ Great advances in GC column methodology have been respond ible for a vastly increased abil ity to analyze nanogram levels of individual hydrocarbons routinely in complex environmental samples and to discern

118 the overall hydrocarbon composition of marine samples (M.L. Lee and Wright, 1980; Cram and Yang, 1980; Grob and Grob, 1976, 1977; Bjorseth and Eklund, 1979~. Stainless steel and glass columns packed with a liquid phase adsorbed onto a solid support phase have given way to stainless steel, borosilicate glass, and fused silica glass capillary columns in which the inter for walls of the columns are coated directly with a liquid phase or coated with a support phase on which the liquid phase is bonded (Jennings, 1980 ~ . Increased resolution of complex hydrocarbon mixtures has resulted. In addition, the increased inert- ness of the glass capillary columns affords excellent GC resolution and response of large aromatic molecules (6 rings) and, in the case of nonhydrocarbon compounds, the resolution and response of nonder ~vatized polar molecules le.q., triglycerides, sterols; Cram and Yang, 1980~. in distingu ish inq among d if fer ent Capillary columns are effective sources of hydrocarbons for the same . . . sample. For example, background anthropogenic inputs, recent petroleum additions, and biogenic inputs comprise a typical composite source to marine samples from coastal ~ ea. ions . The existence Of . and . , _ _ In some cases the relative contribution of, these assemblages to a particular sample' s "hydrocarbon fraction" are discernible by high resolution glass capillary GC (or GC2) (Over ton et al. , 1977; Farrington, 1980; Simoneit and Kaplan, 1980; Simoneit, 1978; Thompson and Eglinton, 1978a). Characterization of oils by high resolution GC2 has been discussed by Rasmussen (19761, Crowley et al. {1980) , and Cram and Yang (1980~.' The concentrations of individual petroleum compounds are usually a small fraction of the total hydrocarbon concentration. GC results can be used to obtain individual compound concentrations, obtain the sum of components (e.g. , total n-alkanes), or obtain an estimate for a total concentration comparable to gravimetrically determined values by summing the total resolved plus unresolved hump. This hump, or unresolved complex mixture (UCM) (Farrington and Meyers, 1975; Farrington et al., 1976a; Simoneit, 1978), is a characteristic GC feature of some fresh oils and most weathered oils. AS weathering proceeds and resolved components decrease in concentration, the UCM in both becomes more prominent. Additionally, most non-spill-related environmental samples containing anthropogenic inputs (Reed et al., 1977; Wakeham and Farrington, 1980; Farrington et al., 19803 and many geochemical samples (e.g., Thompson and Eglinton, 1978a,b) contain UCM material which may account for 80-90% of the total hydrocarbon weight. The UCM, which most likely consists of naphthenic, naphthenoaromatic, and other condensed ring structures, may be reduced in size but not eliminated by use of the more efficient capillary columns now available. There are techniques (Sampling and Sample Preservation section) that can separate, for example, PAH compounds from the UCM, and n-alkanes from UCM material. However, the shape of the UCM and its molecular weight, and the possible existence of Modal UCM distributions, can prov ide information on the nature of the contaminant oil and postspill diagenetic, metabolic, and selective bioaccumulat~on processes. Indeed, Saxby (1978) and Butler (1975) have used UCM shapes and responses to obtain information on petroleum weathering processes.

119 Thus, GC2 integration algor ithms must be able to integrate peaks over chang ing basel ines ~ i . e ., the UCM} . In practice, a small amount of fractionated extract, as determined by the weight of a given extract, is injected into a GC inlet system or directly onto a glass capillary column (Grob and Grob, 1978a,b). The peaks recorded by the instrument are identified and quantified by one of several methods: (1) comparing retention times of the peaks with those of known standards, (2 ~ determining the retention indices (Kovats and Kealemans, 1964; M.L. Lee et al., 1979) and comparing with those of known compounds, (3 ~ coin jecting a sample wi th standards, or (4 ~ using supplemental analytical equipment and techniques (see Gas Chromatog- raphy/Mass Spectrometry section). Use of retention times is prone to considerable variation from day to day on different instruments and even on the same instrument. Systems of retention indices have been developed to take these variations into account and to make data more reproducible within a given laboratory and between laboratories. There remains, however, the possibility that two components in the sample may have the same retention times and indices on a particular column (i.e., they coelute), even with high resolution techniques. Therefore, unless part of a predictable pattern (e.g., the n-alkanes, isoprenoids), the identity of a component should be verified by (1) injection of the sample on another GC column with a liquid phase of different polarity or (2) supplemental instrumental techniques {GC/MS). - Compound Quantification A variety of quantifying techniques has emerged in recent years. Sample components may be quantif fed by the use of an internal standard method. In this technique, one or mor e components with a molecular structure similar to the compounds being analyzed are spiked to the sample pr for to extraction. Deuterated standards are becoming more widely used, as they eliminate the problem of finding a standard which, a priori, can be determined not to be in a sample {Cretney et al., 1980~. The standard (s) and sample extract are thus carried through the entire analytical procedure . Peak areas of sample components are compared with those of the known quantity of internal standard. The external standard method involves spiking of standard (s) to the extract just pr for to GC analysis . This quanta i- cation method must be corrected for the absolute recovery of the analytical procedure, which is usually accomplished by use of a spik ing or recovery standard and which is, for all intents and purposes, equivalent to the internal standard. The instrumental calibration method involves GC analysis of an aliquot of the sample extract and comparison of instrumental response to that of a known amount of standard compounds run in a separate serial dilution to obtain a calibration curve of instrumental response versus amount injected. this latter technique, both sample recovery and correction for the injection volume must be taken into account. Selective Detector s A var. iety of GC detector s has been developed . _ They are presently in use, either singularly or in combination, to increase the sensitivity and discr imination power of the GC techniques (Hartmann, 1971; Hrivnac et al., 1976; Searl et al., 1979; Novotny et

120 al., 1980a,b; Frame et al., 1979; ASTM Method D 3328-78; Overton et al., 1980b; D.A. Miller et al., 1981~. Data Acquisition, Handl_ ~ and Storage Given the present high level of detail of petroleum hydrocarbon GC determinations, many laboratories have instituted systems for acquit ing, processing, calculating, stor ing, and retr ieving data on mar ine environmental samples . Raw data from high resolution GC2 analyses consist of sets of GC retention time and peak area data. Several independent systems are now in use in analytical laborator ies for transmitting these pairs to an external computer and converting data to peak names ~ i.e., compound names and/or r etention indices based on a standard-) and concentrations, and for storing, retrieving, displaying, and manipulating data (e.g., Overton et al., 1978a,b; Reese, 1980a,b). However, due to the great abundance of data of this nature generated from high resolution GC2 techniques, acquired data should be treated as a library of information on hydro- carbon and other compounds of potential use in (a) monitoring temporal changes of known pollutant compounds of concern, and (b) yielding information on compounds of which the significance has yet to be r evealed . Fur ther hardware and sof tware advances will be needed to link the activities of compound identification, compound quantifi- cation, information storage, information editing, insertion into interlaboratory data files, and selective retr ieval of data for display . Gas Chromatograph ic Mass Spectrometry Gas chromatographic mass spectrometry (GC/MS) is a technique wherein a mass spectrometer acts as the detector of a GC system, thus enabl ing the mass spectr a of elut ing components to be determined . Computer - assisted capillary GC/MS techniques (GC/MS/DS, where DS are data systems), are the most powerful tools available to confirm the identity of and to quantify trace levels of individual petroleum hydrocarbon components in environmental samples. The identity of an unknown compound can be determined by matching the compound' s mass spectrum with that of the pure compound, either manually or via computer- assisted mass spectral library searches and probability-based matches. GC/MS computer systems have been used extens~vely in recent years for unambiguous identification and quantif ication of petroleum and combustion-der ived aromatic hydrocarbon compounds in sediments (Teal et al., 1978; Hites et al., 1980; youngblood and Blumer, 1975; Lake et al. , 1980; Over ton and Laseter , 1980), marine tissues (Grahl-Nielsen et al., 1978; Boehm et al., 1981b; Farrington et al., 1980, 1982a,b; Warner et al ., 1980 ), and seawater {Boehm, 1980a) . GC/MS has also produced valuable data on low levels of saturated hydrocarbon marker compounds in sediments (Simoneit and Kaplan, 1980 ; Atlas et al ., 1981 ; Dastillung and Albrecht, 1976: Albaiges and Albrecht, 1979: Bieri et al., 1978) and in tissues (Anderlini et al. , 1981} . Novel molecular f ingerpr inting techniques using aromatic hydrocarbon and organosulfur compounds (Over ton et al. , 1981), acyclic isoprenoids, steranes, and triterprenoids (Albaiges, 1980) are rooted in GC/MS analyses. GC/MS is - . .

121 also the most powerful method for examining the identity of photochemical and biodegradative (Overtop et al., 1980a) products and metabol ites of parent hydrocarbon compounds . Indeed, GC/MS computer systems could provide a method for determining more components of the UCM GC2 signal. GC/MS is either performed in the chemical ionization (CI) mode (Warner, 1978) or in the more commonly utilized electron impact {EI) mode. In the latter case, the h igh energy ~ ionization voltage = 70 eV) of electron impact results in a high degree of fragmentation of nonaromatic hydrocarbons. CI, using methane as the ionizing gas, results in the preservation of the molecular ion (molecular weight) peak, thus facilitating identification of easily fragmented compounds such as the alkanes. In addition, specialized techniques such as plasma Resorption probe CI (PD/CI/MS) have been developed for use in identifying thermally labile PAH metabolites (Krahn et al., 19801. Basically, GC/MS systems are operated in one of several operational modes: 1. Acquisition of full range mass spectral data, which allows for total ion chromatograms (equivalent to GC/FID trace) and selected ion chromatograms or mass chromatograms to be reconstructed (i.e., computer searches and display of particular fragment or molecular ions characteristic of a compound}. This mode is used to find information on unknown compounds or on a large number (>20) of compound spectra. 2. The selected ion monitoring (SIM) mode allows the mass spectrometer output to be scanned at preselected masses and the resultant mass chromatograms to be stored. SIM allows for greater sensitivity but permits only a limited number of masses to be scanned during a run. 3 . In the probe distillation mode sample, mixtures are introduced directly into the ion source of the mass spectrometer. Increased mass dwell-time greatly increases the sensitivity of this mode so that compounds undetectable in the total ionization modes can be detected (Youngblood and Blumer, 1975; H ites et al ., 1980 ~ . However, this mode is subject to interference by nontarget compounds present in the sample. Quantitative GC/MS by mass fragmentography involves the computer integration of an ion current plot (molecular ion or fragment ion) for a compound derived from the mass chromatogram, comparison to an internal standard ion current , and correction based on relative mass spectral response factors. Although research has been conducted on applications of this technique for several years, extensive rigorous qual ity control and internal iteration are still needed. More details of the var. ious applications of GC/MS are found in Warner (1978), Warner et al. {1980), and Hites et al. (1980~. Other Methods Less widely used analytical chemical methods have been appl fed to measurements of hydrocarbons in mar ine samples. Stable isotope ratios

122 of carbon, sulfur, and hydrogen have been used to examine the hydro- carbon composition of oils and sediments (J.W. Miller, 1973; Sweeney et al., 1980) and to identify weathered oils (Hartman and Hammond, 1981~. Nuclear magnetic resonance {NMR) spectroscopy has been used to examine the relative molecular composition of petroleum constituents and fractions (Petrakis et al., 1980; Petrakis and Edelheit, 1979~. Low-Molecular-Weight Hydrocarbons: Analytical Methods Hydrocarbons in the Cl-Clo range are not amenable to routine solvent extraction techniques. Specialized techniques have been developed for isolating and analyzing Cl-Clo saturated and aromatic hydrocarbons in seawater (Lysyj et al., 1980; McAuliffe, 1971, 1980; Swinner ton and Linnenbom, 1967, 1976; Sackett and Brooks, 1975; Brooks et al., 1980; Sauer et al., 1978), sediments (May et al., 1975; Bernard et al., 1978), and marine biota (Chester et al., 1978; L.C. Michael et al., 19801. The methods that all rely on GC and/or GC/MS as the final analytical tool fall into six categories: static headspace sampling (Friant and Suffet, 1979), dynamic headspace purge (May et al., 1975; Chester et al., 1978; Michael et al., 1980), gas stripping (Sauer et al., 1978; Swinner ton and Linnenbom, 1967, 1976; cellar and Lichtenberg, 1974; Lysyj et al., 1981), vacuum stripping or degassing {Brooks et al., 1973) , multiple phase equilibrium (McAuliffe, 1971, 19801, and direct aqueous in jection . In the static headspace technique, a sample in a closed container is usually heated, and a subsample of the air is taken with a syringe and injected into a gas chromatograph. The method suffers from being suitable to analyze only high concentrations of compounds Of high volatility, although the volatility limitation is improved by heating. Additionally, rigid control of temperature and headspace volume is required. Dynamic headspace techniques involve continuous movement of inert gas (e.g., helium) through the headspace of a heated flask con- taining the sample and the collection of the entrained volatiles on an accumulator column, e.g., Tenax GC (Michael et al., 1980; Chester, 1978~. This method is appropriate for use with biological samples but has also been used for sediments (Bernard et al., 1978; May et al., 19753. Nonvolatile hydrocarbons left behind may be analyzed by high- molecular-weight hydrocarbon methods. In gas stripping, the inert gas is bubbled through the sample, and the purged vapors are trapped on a sorbent (Tenex GC, Porapak Q. alumina or activated charcoal columns). The method is best suited for seawater analysis, as severe foaming limits its use for most biological samples (Michael et al., 19801. Swinnerton and Linnenbom (1967 , 1976) and Sackett and Brooks (1975) have used gas stripping to isolate gaseous hydrocarbons from seawater, and Sauer et al. (1978) used the method to isolate volatile liquid (C6-C14) hydrocarbons from seawater. Lysyj et al. (1981) trapped sparged aromatic hydrocarbons from seawater, trapped them in activated charcoal, desor teed them with carbon disulfide, and directly injected the solution into the GC. The sensitivity was 0.1-0.2 ug/L. Given the proper design of adsorption and desorption systems, the gas

123 str ipping techniques are suitable for nL/L levels of low-molecular- weight hydrocarbons (Brooks et al. , 1980~ . Use of a vacuum stripping apparatus, The Sniffer" by Brooks et al. ~ 1973 I, involved continuous str ipping of gaseous hydrocarbons from seawater by vacuum degassing. The apparatus is used by the petroleum industry for routine sampling to detect dissolved gases near suspected seep areas. The system consists of a tow body, a pump, and shipboard degassing apparatus, interfaced to provide an analysis at 90-s time intervals. The multiple gas phase equilibrium approach of sample analysis has many appl ications to oil spill and other environmental studies {McAuliffe, 1980~. While gas stripping techniques are partial equi- librium methods, the gas equilibration technique provides for transfer of volatile constituents from water to inert gas in proportion to the compound's vapor pressure and aqueous Volubility (i.e., distribution coefficient). The inert gas is injected directly into a GC. The technique, as described by McAuliffe (1980), is well suited for spill-related studies and has been used extensively in experimental spill studies by McAuliffe et al. (1980) and in studies of New York harbor by McGowan (19751. Direct aqueous in jection onto a GC column is 1 imited by high detection limits (mg/L) (ASTM Method D 2908-74), although the method may be used in conjunction with capillary GC to increase sensitivity. All methods require special ized GC introduction systems for the efficient thermal Resorption of trapped mater ial (e.~., Michael et al., 1980 ~ onto the head of a GC column, and for the selective removal of water from columns prior to Resorption. PETROLEUM HYDROCARBON INTERC=IB~TION/IN=~~I SON PR=~S Interlaboratory intercalibration programs of various types have been undertaken with national and international scopes. The intent of these studies has been mainly to examine the variability of analytical results between labor ator ies, aid in the evaluation and compar isons of environ- mental data sets, evaluate the relative efficacy of different methodol- ogies, and improve analytical methods so as to reduce interlaboratory discrepancies in data. In recent years, researchers have developed specialized techniques for analyzing hydrocarbons in marine samples. Comparison of analytical data developed in different studies has often been highly problematical, even among programs (data sets) utilizing similar basic analytical tools (e.g., capillary gas chromatography). The problem is, of course, more severe when one attempts to relate data sets which have utilized different analytical techniques (e.g., fluores- cence spectroscopy and gas chromatography). Many laboratories are involved in the measurement of fossil fuel hydrocarbons in marine samples utilizing different techniques. There is currently little available information on the computability of these data sets. Three types of interlaboratory comparison exercises are possible: (1) sample splits involving relatively few laboratories, (2) calibra- tion samples or sample extracts prepared for specific research or

124 monitoring programs, and (3) standard certified reference materials. The most significant intercalibration exercises presently underway or previously undertaken address type (1) exercises, involving enough laboratories to enable statistical analysis of data. Type {3) materials with National Bureau of Standards (NBS) certification, containing known amounts of specified constituents, have been requested by scientists in environmental studies. To date, only one such sample has been prepared, due to uncertainties of sample homogeneity, storage stability and matrix ef feats, and definitive analytical methods. A new standard reference material (SAM 1580), "Organics in Oil Shale,. is intended primarily for evaluating reliability of analytical methods for the determination of three PAR and two pl.~.enolic compounds in an oil matrix. Thus, most exer- cises involve type (2) programs. A summary of major petroleum hydro- carbon intercalibration studies undertaken in the 1976-1981 period is shown in Table 3-2. Interiaboratory precision has improved signifi- cantly over the past 5 years or so, as techniques for both analyzing samples and running intercalibration exercises have improved. The roots of a well-conducted intercomparison program lie in the homogeneity of the sample and the comparability of data (i.e., the reporting of the same components by all participating laborator ies on the same basis, corrected for recovery) . Dur ing the last 5 years, the ability to conduct intercalibration exercises and to analyze samples rigorously and achieve comparable results have both improved markedly. Bearing in mind that there is no fright answer" in such exercises using environmental samples, a group of laboratories in the United States has obtained generally tightly grouped results based on GC2 {and GC2/MS) determined alkane and polynuclear aromatic hydrocarbon levels in sedi- ments (MacLeod et al., 1981a). While statistical evaluations are still in progress, laboratories probably can achieve comparable (within a factor of 2 and often much better) analytical results. Coefficients of variation for individual aromatic hydrocarbon determinations in the Duwamish II study were, for example, +14% for fluorene, +17% for phenanthrene and fluoranthrene, and +39% for perylene, for the six data sets (MacLeod et al., 1981a) and were as good for n-alkane values. The International Council for the Exploration of the Seas (ICES) intercalibration studies, while not as rigorously controlled as the Duwamish exerc ises ~ see Table 3-2 ), have yielded compar able f luor es- cence-based data on sediments with a coefficient of variation for "total petroleum" in the 10-308 range. This level of agreement was reached by using specified quantification methods, i.e., prescribed Integrated Global Ocean Station Systems (IGOSS) wavelengths. The ICES-sediment exercise yielded comparable W-, OR-, and GC-based Total hydrocarbon. concentrations. Intercalibrations on biological mater ials have posed more serious problems, with even W-based data (ICES study) yielding poor results, probably due to both analytical problems and quantification techniques. The GC- and GC/MS-based EPA megamussel study currently under way (no f inal data available) specifies individual compounds and aromatic isomer ic groupings for reporting. The emerging view appears to be that, for the most part, comparabil- ity of petroleum hydrocarbon and PAM results is beginning to depend

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128 more on the quantification process ~ i .e ., how individual component GC peaks are quantified) than on the extraction and process ing steps (i.e. , several extraction procedures will suffice). This is true for the Duwamish I and II sediment studies, wherein differing extraction methodologies were used (D.W. Brown et al., 1980; MacLeod et al., 1981a), and may be emerging as the reason behind variability in the more difficult, interference-prone biotic measurements. Clearly, further intercomparisons are required, addressing (1) comparability of results based on simpler, more universally available methods (i.e., W fluorescence), (2) comparability of more rigorous techniques (i.e., GC and GC/MS), (3) intercomparability of the methods, and (4) the location within the analytical technique for discrepancy. Laboratories should be urged to participate in intercalzbration pro- grams in a nonthreatening atmosphere at the start of the environmental chemistry program, to enable the refinement of analytical techniques so as to achieve results within a determined statistical range. The NBS SRM oil shale, samples such as Duwamish I and II sediments, and the ICES sediment appear to be most appropriate for this purpose. REMOTE DETECTION AND MEASUREMENT OF OIL SPILLS Remote sensing devices used to monitor marine pollution are becoming more sensitive and reliable than they were just 5 years ago. The use of both airplanes and satellites as platforms for remote sensing devices has been explored. ICES and NOAA, as well as other organiza- t~ons, have been involved in the development of satellite-carried equipment for sensing oceanographic parameters (Apel, 1978; Kniskern et a-l., 1975; Koffler, 1975; N.R. Anderson, 1980; Klemas, 1980~. However, satellite monitoring is not without problems. Geosynchronous satellites do provide repeatable coverage, but the resolution is not great enough to be of practical use. The NASA ad hoc committee on remote sensing concluded that the physical parameter requirements for oil spill monitoring are at least an order of magnitude greater than the remote sensing data which are now available {Croswell and Fedors, 1979~. In addition, Goldburg (1979) concluded that sensors in airplanes are more feasible and cost efficient than satellite remote sensing, thus, the focus on airborne sensors in this section. The U.S. Coast Guard has developed remote sensing "packages to aid in the detection of oil slicks. The two prototypes of the current package, AOSS I and AOSS II (Airborne Oil Surveillance Systems ~ and TI), are described more fully in Bentz (1980), Maurer and Edger ton (1975), and G.P. White and Arecchi (1975~. The third-generation aerial reconnaissance system, designated AIREYE {for aerial remote instrumenta- tion), will be installed in Falcon 20-G jet planes and includes side- looking airborne radar (SLAR,, an IR/ W scanner, a computerized data recording system, and an aerial reconnaissance camera (N.R. AndersOn, 1980~. By including sensors utilizing three portions of the electro- magnetic spectrum, the number of false alarms due to kelp beds, wake scars, and the weather can be kept to a minimum (J.R. White et al., 19791. .

129 Remote sens ing devices can be divided into two categor ies: those based on passive (natural) reflectance and emission of some part of the electromagnetic spectrum, and those based on an active (man-induced) electromagnetic excitation of the ocean sur face and the collection of reflected radiation. The passive group includes microwave, IR, and W collectors. Those devices that depend on man-induced electromagnetic radiation include radar, W fluorescence systems, and laser backscatter sensors. Table 3-3 (from N.R. Anderson [1980] and Maurer and Edger ton [19751) reviews the types of remote sensing devices and the false alarms g iven by each. Passive microwave systems measure radiation waves naturally emitted or reflected by the sea surface. Microwave brightness is a function of surface roughness and the dielectric constant of the surface. Thin oil films have a calming effect on the water surface, which results in a modification of the microwave structure and thus a lower brightness temperature. Thick films (~0.1 mm) emit more microwave energy than unpolluted water does; thus, the film thickness can be determined from the relative brightness temperature. Passive microwave systems can penetrate weather and are independent of lighting conditions. Disad- vantages include coarse resolution and a limited swath (Maurer and Edgerton, 1975~. Infrared sensors detect apparent temperature differences between oil and water due to the physical properties of the two substances. Oil and water have different reflectance properties in the 2- to 4-pm spectral range (G.P. White and Arecchi, 19751. In the near IR range (0.6-1.1 um), the radiance from an oil slick is 20-100% greater than the radiance from water, and at night, oil gives 50% greater radiance than water does (Catoe, 1972~. Thermal IR (1.1-14 um) sensing is limited to specific atmospheric windows where the atmosphere is trans- parent enough to allow the waves to pass through without significant absorption (Catoe, 1972~. Thermal infrared sensing can also be used 24 hours a day, and IR waves can penetrate haze but not clouds. Odd local thermal structures {e.g., an upwelling) can cause false alarms (Maurer and Edgerton, 1975~. Passive ultraviolet collectors can detect oil patches because oil reflects more W light than water does. The greater amount of W radiation that water absorbs, the cooler it appears in relation to the oil slick it surrounds. Passive W collectors require some ambient sunlight, but the light range can be extended if the collector is used in conjunction with a low light level television (LLLTV). False alarms from this system include kelp patches (Maurer and Edger ton, 1975), and atmospheric aerosols limit its use in hazy weather (Catoe, 19721. One of the more widely used active sensing systems is radar. It is used with a great deal of success to detect offending ships and oil slicks on the sea surface. SLAR has a swath of up to 80 km (40 km on each side of the airplane). SLAR detects the capillary wave-damping effect caused by oil on the sea surface, so this technique becomes ineffective on flat, calm or extremely rough seas. Another disadvantage of SLAR is that it does not "see" a strip directly beneath the plane. An IR/ W line scanner is often used to overcome this problem (J.R. White et al., 1979).

130 TABLE 3-3 Oil Spill Detection by Remote Sensing: Sensors and Spectral Regions Sensor Spectral Approach Region Active reflectance Microwave radar, 1.05-5 cm Laser backscatter W fluorescence, 0.4 m Passive W , 0.4 m reflectance Visible 0.4-0.65 m Near IR, 0.65 m Passive Thermal IR, emission 3-14 m Microwave, 0.2-1 cm False Alarmsa Natural organic slicks Wind slicks, ship wakes Pollutant organic slicks (detergents, sewage sludge) Kelp/debris Dense cloud cells Unrippled water under calm conditions Natural organic slicks Suspended sol ids Natural organic slicks Pollutant organic slicks Suspended sol ids Shallow water Broken cloud deck Natural organic slicks Other pollutant slicks Natural organic slicks Pollutant organic slicks Ship wakes Thermal discharges and effluents Upwelling Foam patches Kelp/debris Dense cloud cells Has all of the listed sensors detect oil on water, natural petroleum seeps would be a false target for each sensor. SOURCE: N.R. Anderson (1980) and Mauer and Edgerton (1975). A laser backscatter sensor (Dichromatic Lidar Polarimeter), which transmits at two coaxially aligned, vertically polarized wavelengths, has been developed (G.P. White and Arecchi, 1975) . Depolarization occurs at the sea surface, and the two wavelengths are backscattered differentially. The backscatter is collected, and the magnitude of returned radiation and the depolarization ratios are used to determine the presence of oil. Hoge and Swift (1980) used a laser-induced water

131 Raman backscatter sensor to detect the presence that oil depressed the Raman backscatter, which of oil. They found r eturned to normal after the sensor was over water once again. Oil film thickness could also be determined using this method . Probably the most promising remote sensing device currently being developed is the laser-induced W fluorescence sensor. Laser-induced fluorescence systems not only differentiate oil from water but also can discriminate between oils as well (Kim and Hickman, 1973; Rayner et al., 1978; Fantasia et al., 1971; Fantasia and Ingrao, 1973; Horvath et al., 1971; O'Neil et al., 1975; Measures et al., 1975; Rung and Itzkan, 19761. A W laser excites the sea surface, and the fluorescence return ~ s collected. A photomultiplier tube converts the fluorescence to an electrical signal, and then a fluorescence spectrum can then be printed out. Field trials by Fantasia et al. (1971), Horvath et al. (1971), and Rayner et al. (1978) have shown that, not only can oil fluorescence be detected over background fluorescence, but oil can be classified into three groups: diesel fuel, crude oil, and bunker fuel. O'Neil et al . (1980) reported that oil shows increased W absorbance with decreasing excitation wavelength; thus, thinner oil layers can be detected. The shorter wavelengths also show greater structure in the fluorescence spectra, which gives greater discrimination power and allows c lass if ication of d if fer ent o its . Attempts have been made to detect oil in the water column using W fluorescence sensors. These have been almost totally unsuccessful because there is so much nonpetroleum suspended organic matter in seawater and, because water absorbs so much W light, there is very little fluorescence emitted (F.E. Hoge, personal communication, 1981) \ MONITORING FOR PETROLEUM HYDROCARBONS The success of any monitor ing program depends on the proper selection of environmental parameters to be measured, the proper choice of analytical techniques to be used, the comparabil ity of analytical results over time and between labor ator ies, and the statistical validity of the measurements (i.e., what level of sampling and analytical effort will detect change) (Risebrough et al., 1980~. also the Introduction to this chapter.) When the amounts of oil are large, simple analytical techniques (e.g., IR, gravLmetry) or remote sensing may suffice. However, at low levels, analytical strategies become critical. A specific property of the oil such as W/F may be determined and "equivalent oil concentra- tions" obtained. Alternatively, individual components in a single class of compounds (e.g ., aromatic hydrocarbons) may be quantif led. Measurements of specific properties, although more widely performable by more laborator ies, rely on tenuous assumptions regarding cal iteration of -the methods . Monitor ing of individual compounds is more expensive and requires extensive quality control and intercalibration. However, much useful information for dif ferentiation between hydrocarbon sources can be obtained, along with determination of the extent and severity of .

132 pollution. If seawater is the targeted environmental compartment, then W /F may suffice due to low background levels. In cases where correla- tion analysis of hydrocarbon and other parameters is used as a monitor- ing tool' then these simpler techniques may differentiate impacted from nonimpacted sediments (Boehm and Quinn, 1978~. However, most monitoring scenarios call for specific chemical component measurements, perhaps guided by specific property techniques {see Figure 3-3~. Several far-reaching analytical monitoring programs have been initiated in recent years which address two main concerns: (1) detection of environmental change (i.e., environmental degradation or improvement) due to petroleum hydrocarbon (and other pollutant) inputs to the system, and (2) assessment of the temporal recovery of an oil spill stressed system. A third concern only loosely being addressed due to constraints of time and data handling is the identification of "new pollutants.. One example of the former type of program is the U.S. EPA Mussel Watch program (National Academy of Sciences, 1980; Farrington et al., 1983), which utilizes the sentinel organism approach. Mussels on the mid-Atlantic, northeast, and west coasts, and oysters on the southern and Gulf coasts are analyzed for specific petroleum hydrocarbons and other pollutants, the rationale being that mussels reflect the water quality over an integrated time scale. Emphasis in the hydrocarbon program is on analysis of specific aromatic compounds (currently up to 4 rings) and alkylated aromatics to determine absolute levels of these compounds, their changing levels, and sources of observed hydrocarbons (i.e., whether from pyrolytic or petroleum sources). Intercalibrations have been underway in this program (Galloway et al., 19837. NOAA's Northeast (U.S.) Monitoring Program attempts to link chemical to biological parameters over time. The focus is on the analysis of sediments as a major sink for pollutants, and a selected set of organ- isms for individual PAH {and polychlorinated biphenyls (PCB) and metals) compounds. This program attempts to utilize several preexisting data bases (BLM-Benchmark; NOAA-MESA [New York Bight]), although in the past no uniform techniques of measurement have been utilized nor inter- calibrations stressed. ICES monitoring programs, in existence since 1977, have focused on metal and organochlorine residues in sediments and several fish and invertebrate species. Petroleum hydrocarbon information is beginning to be derived from this program, mainly based on specified W /F analysis, but presumably to be complemented by high resolution tech- niques as well. Residue levels are evaluated in terms of human health concerns . The ICES ~coordinated" monitor ding programs include part of NOAA's Northeast (U.S.) program as well. This program now proposes to keep the following regions under annual surveillance: Irish Sea; German Bight, Southern Bight of the North Sea; the Estuaries of the Forth, Thames, Rhine, Scheldt, and Clyde; the Skagerrak, Kattegat, and Oslo fjords; plus certain parts of the Gulf of Saint Lawrence and New York Bight. The ICES program has three monitoring rationales: (1) the provision of a continuing assurance of the quality of marine foodstuffs with respect to human health, (2) the provision, over a wide geo- graphical area, of an indication of the health of the marine environ

133 ment in the entire ICES North Atlantic area, and {3) to provide an analysis of trends in pollutant concentrations. Intercalibration exercises for petroleum (see Petroleum Hydrocarbon Intercalibration/ Intercomparison Programs section) are underway, although many dis- crepancies in methodology need to be resolved. Monitoring for the recovery of systems following oil spills has been conducted for many spills. Once a choice of sampling stations and measurements has been made, the same concerns face these programs as well as the "baseline-type" programs. Examples of spill monitor ing programs are: Arrow shill (Keizer et al ., 1978 ), West Falmouth shill (Teal et al., 1978), Tsesis spill (Linden et al., 1980; Boehm et al., 1981b), Amoco Cadiz spill (Atlas et al., 1981), and Iranian Crude- Norway spill (Grahl-Nielson et al., 1978) . All relied on detailed chemical measurements of sediment and/or biota to monitor based on the decrease and/or modif ication of petroleum residues . - ~ recovery CONCLUSIONS AND RECOMMENDATIONS Conclusions No single method of analysis provides a measure of total petroleum in water, sediment, or tissue because of the extreme complexity of the composition of petroleum. Unfortunately, apparent economic necessity has often forced analysts to the less expensive and less discriminating methods of analysis with attendant generation of a substantial amount of data which can only be interpreted with large uncertainty. However , improved methodology for measuring fossil fuel compounds has been rapidly developed or applied since the 1975 NRC report. The range of selectivity and sensitivity makes it essential to choose the correct methods for a particular problem and to recognize the inter- pretation limits for the data. Recommendations Quality Control and Intercomparison of Data The rapid increase in the number of analysts and the demand for larger sets of data require careful quality control and intercomparison of ~ ~ ~ ~ ~ ~ ~ ~~~~ NRC report. data, now even more than at the time of the 1975 We recommend that rigorous quality assurance protocols be integrated into the analysis of hydrocarbon and other fossil fuel compounds in environmental samples. The value of standard solutions, spiked samples, spiked extracts, and sample homogenates for quality control and intercomparison has been demonstrated in a few studies.

134 Identification of Sources of Input Many studies of petroleum inputs or distr ibution in the mar ine environ- ment have not appl fed analytical techniques to identify sources mor e exactly. The terms "petroleums" and petroleum hydrocarbons" are often used incorrectly and too loosely when describing data resulting from less discr imitating analyses. This Is especially true in regard to inclusion of pyrogenic source hydrocarbons within the data for petroleum. Application of Analytical Methods We recommend the application of analytical methods with sufficient sensitivity and resolution to identify the various sources of input, e.g., high resolution glass capillary/gas chromatography/mass spectrometry/computer systems analysis or high performance liquid chromatography analysis coupled with mass spectrometry computer systems. Nonhydrocarbon Compounds in Petroleum Because many of the nonhydrocarbon compounds in petroleum are bio- log~cally active, we recommend a more concerted effort to measure these compounds in studies of inputs, fates, and effects _ Metabolites and Photochemical Reaction Products The concern about the biological activity of several metabol ites and photochemical reaction products as indicated in the fates and effects sections leads us to recommend research into methods for measuring these compounds in samples from laboratory and field studies. These methods would be used in studies of biogeochemical processes acting on fossil fuel compounds and in studies of biological effects. We do not advocate extensive analytical chemistry data-gathering exercises in monitoring program measurements of metabolites and reaction products until such time as research has clearly demonstrated the usefulness of such an approach. Rather, we recommend the investigation of biochemical or physiological parameters as potentially more useful for determining where biologically active compounds have been or are present. Remote Sensing Sensors of various types have been tested from aircraft and show promise for providing useful information in the measurement of the areal extent and thickness of slicks. We recommend further testing in conjunction with sea truth measurements to evaluate this concept further.

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This comprehensive volume follows up and expands on an earlier National Academy of Sciences book. It is the result of an intensive multidisciplinary effort to assess the problems relating to petroleum-derived hydrocarbons in the marine environment. Specifically, it examines the inputs, analytical methods, fates, and effects of petroleum in the marine environment. The section on effects has been expanded significantly, reflecting the extensive scientific effort put forth in determining the effects of petroleum on marine organisms. Other topics discussed include petroleum contamination in specific geographical areas, the potential hazards of this contamination to human health, the impact of oil-related activities in the northern Gulf of Mexico, and the potential impact of petroleum on fisheries.

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