Computer simulation of active air sampling for volatile organic compound analysis

Abstract

A study of the literature reveals that published breakthrough volumes do not take into account the findings of other studies into the effects of competitive adsorption in active sampling for volatile organic compound analysis. A model-based approach for estimating breakthrough volumes under different sampling conditions is proposed and described. Simulations of sampling a binary mixture of volatile compounds illustrate how breakthrough volumes can vary significantly. Further, tests under laboratory conditions indicate that changes in breakthrough volumes may be reliably estimated by this approach, although the predictions were not as accurate when used to estimate 5% breakthrough volumes based on previously published work. Nevertheless, the shortcomings of using published safe sampling volumes in the development of sampling protocols are clearly demonstrated, and the approach described is a practical response to overcoming this problem.