Strategies to Protect the Health of Deployed U.S. Forces Detecting, Characterizing, and Documenting Exposures (2000) / Chapter Skim
Currently Skimming:
Appendix D Detecting and Monitoring Chemical Agents
Appendix D Detecting and Monitoring Chemical Agents
Pages 191-211
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 191... ...
Spectroscopy is the use of the absorption, emission, or scattering of electromagnetic radiation by atoms or molecules (or atomic or molecular ions) to qualitatively or quantitatively detect atoms or molecules (Scimedia, 1999~.
|
From page 192... ...
operates by drawing air at atmospheric pressure into a reaction region where the constituents of the sample are ionized. Air and chemical agents in vapor-phase compounds form ion clusters when they are exposed to their parent ions.
|
From page 193... ...
The wavelength of infrared absorption bands work best for identifying organic and organometallic molecules (Dean, 1995; Scimedia, 1999~. Compounds in the air that absorb infrared energy can be quantified using open-path Fourier transform infrared (FTIR)
|
From page 194... ...
194 be ._, o .
|
From page 195... ...
Aerosol Mass Spectrometry The goal of aerosol mass spectrometry is to provide on-line, real-time chemical analysis of individual aerosol particles Johnston, 1999~. The chemical analysis characterizes aerosol particles in terms of bulk composition, surface composition, organic chemical species, and inorganic chemical species.
|
From page 196... ...
can be used to detect many chemical agents (Stedman, 1999) and are used for gas chromatography.
|
From page 197... ...
Like mass spectrometry, gas chromatography methods also offer high sensitivity and specificity in detecting chemical agents in many sample forms.
|
From page 198... ...
Examples of such "hyphenated techniques" include gas chromatography/mass spectroscopy, gas chromatography/FTIR, and diode-array ultraviolet/visable absorption spectroscopy. Surface Acoustic Wave Technology Surface acoustic wave (SAW)
|
From page 199... ...
Pulses of a specific wavelength of infrared light are sent into a sample through an optical filter, and the light transmitted by the filter is selectively absorbed by the gas being monitored, which increases the temperature and pressure of the gas. Because the light entering the cell is pulsating, the pressure in the cell fluctuates, creating an acoustic wave directly proportional to the concentration of the gas in the cell.
|
From page 200... ...
Army SBCCOM, 1998~. If the absorption of energy at these wavelengths is sufficient, microwave spectroscopy-based technologies similar to infrared spectroscopy methods may be another way of detecting chemical agents.
|
From page 201... ...
Another problem is that some substances do not readily create antibodies. CURRENT DETECTION AND MONITORING EQUIPMENT Currently available equipment for detecting and monitoring chemical agents range from simple systems, such as detection paper, to complex mobile sampling vehicles, such as the FOX vehicle.
|
From page 202... ...
M8 Chemical Agent Detector Paper M8 paper is used by ground troops to detect liquid chemical agents. It is capable of detecting Levinstein mustard (H)
|
From page 203... ...
M22 Automatic Chemical Agent Detection Alarm The M22 is an "off-the-shelf," automatic, chemical agent alarm system based on IMS technology that is capable of detecting and identifying standard blister and nerve agents. The M22 system is man-portable, can operate automatically after system start-up, and provides an audio and visual alarm.
|
From page 204... ...
The M90 is a fast-acting, relatively sensitive device that provides an alarm in about 10 seconds for nerve agents and mustard and about 80 seconds for lewisite. Individual Chemical Agent Detector The ICAD is an 8-ounce pocket-mounted device that simultaneously detects nerve, choking, blood, and blister agents based on electrochemical techniques.
|
From page 205... ...
ICAM-APD can simultaneously detect both nerve and blister vapor and aerosol agents. SAW Mini-Chemical Agent Detector The SAW Mini-CAD is a commercially available, pocket-sized instrument that can automatically monitor for trace levels of toxic vapors of both sulfur mustard and the G nerve agents with a high degree of specificity.
|
From page 206... ...
Although gas chromatography systems take up to 10 minutes for an analysis, they are highly sensitive and very specific, and they can detect most chemical warfare and many toxic chemical agents below the ALL levels. Gas chromatography systems, which are versatile and can detect thousands of chemicals, come with extensive chemical spectra libraries.
|
From page 207... ...
. Stand-off Monitoring Systems The AN/KAS-l/lA chemical warfare directional detector is a FLIRbased electro-optic sensor that remotely detects the presence of nerve agents.
|
From page 208... ...
The JCAD will employ SAW technology to detect nerve, blood, and blister agents. The system is being designed to be lightweight and portable, to reduce the number of false alarms, and to detect new forms of nerve agents.
|
From page 209... ...
Shipboard Automatic Liquid Agent Detector (SALAD) SALAD is an automatic, exterior, liquid agent point detection and monitoring system that will detect and set off an alarm in the presence of liquid nerve and blister agents.
|
From page 210... ...
1999. Chemical and Biological Terrorism Research and Development to Improve Civilian Medical Response.
|
From page 211... ...
1999. Development of Fourier transform spectrometry for UV-visible differential optical absorption spectroscopy measurements of tropospheric minor constituents.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.