Determination of phosgene (carbonyl chloride) in air by high-performance liquid chromatography with a dual selective detection system

Abstract

The development of a sensitive and highly selective method for determining airborne phosgene in the workplace is described. Phosgene was collected in an impinger solution containing tryptamine, as the derivatizing reagent. The derivative was determined by a reversed-phase high-performance liquid chromatograph equipped with dual detectors, fluorescence emission and amperometric oxidation. Limits of detection for both detectors were 8 ng ml–1. As both detectors are selective, the confidence level of the analysis is considerably enhanced. Simulated air sampling for phosgene vapours generated in a glass gas-collecting bulb showed that recoveries were excellent and that the method can be used to detect phosgene at a level of 0.04 mg m–3[a tenth of the threshold limit value–time weighted average (TLV–TWA)] in a 1 | air sample.