Feasibility of Sampling Vapors of Compounds with Low Volatility by Permeation

Abstract

Lindane was used as the model of low vapor pressure compounds for the study of the feasibility of sampling vapors of such compounds by permeation. A constant source of lindane vapor, a dynamic exposure chamber, and a sampler for the chamber air were all based on the permeability of polyethylene (PE) to the vapor. Lindane-saturated air was contained in a glass vial with a thin PE membrane septum; the other side of the film was exposed to the supply air for the chamber. This kept the downstream face at virtually zero. The chamber concentration was monitored for several months by a grab sampler using a polyurethane foam (PUF). The samplers were ∼2 mL autoanalyzer vials with a PE septum backed by PUF sorbent. All operations to this point were conducted in a controlled temperature room. From the chamber concentration and the sampler uptake of lindane it was possible to calculate the coefficient of diffusion (D) for the combination, lindane vapor and a polyethylene membrane (lindane·PE). Using this value for D,...