Molybdenum-Blue Spectrophotometric Method for Determination of Lewisite Vapor in Air

Abstract
A method was developed for determining lewisite vapor in air. The method entails the collection of lewisite in an impinger or solid-sorbent sampler, conversion of the trapped lewisite to arsenite ion, oxidation of arsenite to arsenate, and determination of the arsenate ion by molybdenum-blue spectrophotometry. Relative to other available techniques, the one described here requires a minimum of instrumentation and can be executed without the use of highly toxic lewisite solutions for instrument calibration.