Evaluation of Two Diffusive Samplers for Monitoring Chlorine and Chlorine Dioxide in Workplace Air

Abstract

Two different types of diffusive samplers utilizing an absorbing solution were evaluated for the simultaneous collection of chlorine and chlorine dioxide in workplace air. Sampler A was made of plexiglass, and the diffusion was controlled by drilled diffusion channels. The other type, B, was constructed from a 37-mm aerosol cassette and two Teflon® membranes. The absorbing medium used was a neutrally buffered, 10-mM, potassium iodide solution. The formed chloride and chlorite ions were then analyzed by ion chromatography. The effect of air velocity and concentration on the sampling rates were investigated. The results showed that the sampling rates of both diffusive samplers A and B were constant for different concentrations and air velocities. Field testing of the diffusive samplers was performed with good agreement between the two devices. The tested samplers are both easy to use, and sampler B is very easily built. Diffusive sampler A allows determination of 0.02 ppm chlorine dioxide and 0.07 ppm chlorine with 8-hour sampling, and the corresponding values for sampler B are 0.016 ppm and 0.04 ppm, respectively.