Lewisite detectors

The recent development and comparative application of modern separation techniques with regard to determination of alkylphosphonic acids and lewisite derivatives have been demonstrated. This report highlights advantages and shortcomings of GC equipped with mass spectrometry detector and HPLC as well as CE with UV-Vis detector. The comparison was made from the sampling point of view and separation/detection ability. The derivatization procedure for GC of main degradation products of nerve agents to determine in water samples was applied. Direct determination of lewisite derivatives by HPLC-UV was shown. Also optimization of indirect determination of alkylphosphonic acids in CE-UV was developed. Finally, the new instrumental development and future trends will be discussed. 

Automatic Liquid Agent Detector (ALAD) A liquid agent devise that can detect droplets of GD, VX, HD. and Lewisite as well as thickened agents. It transmits its alarm by field wire to a central alarm unit. 

The foundation of the CWC s inspection activities was based around the declaration by member states of their chemical weapons capabilities and activities. Nations with chemical warfare programmes were required to declare their production, storage and destruction facilities, which would then receive top monitoring priority. Nevertheless, the CWC did allow states to maintain research programmes to ensure the integrity of defensive equipment such as gas masks and gas detectors, but these activities were also to be closely monitored since they involved work with the chemical agents listed on Schedule l.9 Otherwise, all other warfare agents, mustard gas, Lewisite, soman, sarin, tabun, VX and the capability to produce them were to be eliminated under the watchful eyes of international inspectors (Table 8.1).10 The convention thus defined chemical weapons as any toxic chemical, or its precursors, intended for purposes other than those not prohibited under this convention for... 

Agent Detector Lewisite Blood Vapor only 0.8 mg rrT3 80s... 

Lewisite is reported to possess a characteristic (geraniumlike) odor in the range of 0.8 mg/m to more commonly cited 14-23 mg/m median detection (Pechura and Rail, 1993). US forces have detectors for lewisite-paper and kits (M7 and M9A). Other forensic techniques for soil and material analysis already exists (e.g. gas chromatography). In biological tissues, increased arsenic levels are a surrogate for lewisite (Haddad and Wincester, 1983). 

B. The detection of lewisite is facilitated by the fact that it forms colored products with many reagents. Draeger tubes are available which react with organic arsenicals. However, no automatic detectors are available for use in the field. 

The M18 detection kit and the M256A1 kit are mihtary items. The M18 is a colorimetric device for measuring the concentration of selected airborne chemicals. The Ml8 comes with detector tubes for cyanide, phosgene. Lewisite, sulfur mustard, and nerve agents GA, GB, GD, and VX. 

By March 1942 a number of blister gas detectors, all of which were based on color changes in a dye base and had their origins in British and American developments in 1918, had been standardized. They included the M4 vapor detector kit, capable of registering even faint concentrations of nitrogen and sulphur mustards M5 liquid vesicant detector paint M6 liquid vesicant detector paper and M7 vesicant detector crayon, sensitive to mustard and lewisite. Although the CWS had not discovered a better dye base than that developed by the British, NDRC chemists at the University of Chicago, at the University of Virginia, and at Ohio State improved its composition and developed new detector materials. ... 

A recent study published in the Chinese Journal of Instrumental Analysis, Fenxi Ceshi Xuebao, showed a detection limit of 500 ng of Sulfur Mustard (HD) by using accelerated solvent extraction-gas chromatography (ASE-GC) coupled with a flame photometric detector (EPD) in the sulfur mode, in soil. In this case, the study showed evidence that ASE results in better recoveries and sensitivity than liquid solid extraction (LSE) [50]. In 1996, a paper was published on a method for the analysis of Lewisite through derivatization of the compound before introduction into a gas chromatograph. In order to simplify the derivatization process, a tube packed with absorbent was used for collection of airborne vapors. If a positive response occurs when screening analytes using a GC coupled with an FPD, then the same sample can be analysed using a GC equipped with an AED for confirmation based on the elemental response to arsenic (in the case of Lewisite) and sulfur (in the case of Sulfur Mustard) within the appropriate GC retention time window [54]. 

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