Abstract
The performance of three commercially available diffusion samplers exposed to different concentration-time profiles of organic vapors in air was evaluated to investigate the possibility of sample loss. Separate sets of experiments were carried out for ethyl benzene, methyl ethyl ketone, n-hexane and 1,1,2,2-tetrachloroethane. Time-weighted average concentrations estimated from diffusion samplers were compared with the TWA's from continuous infrared absorption measurements. The overall mean bias was +7.0%, although considerable difference from the mean bias was observed for individual combinations of sampler brand, exposure profile and compound. The overall coefficient of variation was 6.4%. No significant sample loss was observed, but the bias was more negative for constant concentrations levels near the PEL and for shorter exposures at higher concentrations.