Sampling with Gas Bags I: Losses of Analyte with Time

Abstract

Very little information is available in the literature concerning the utility of various bag materials for the collection of volatile organic chemicals. This study looks at the losses with time of collected organic vapors from Saran, Teflon, Tediar, Halar and a five-layer aluminized bag. The analytes tested consisted of methanol, acetone, butene, butadiene, benzene, and trichloroethylene. There was a loss of collected analyte with time for all of the compounds tested and all bag materials. In general, Tediar bags seemed to be the best choice for short-term samples (storage time of ≤ 4 hours). Aluminized bags, as distinct from all the others, did not show a continuous loss of analyte with time; a leveling off after initial loss was observed. This behavior suggests that these bags might be useful for transporting standards into the field for calibration purposes provided they are pre-equilibrated before filling. Further work is under way to determine which factors are important to the loss process for Tediar and aluminized bags. Posner, J.C.; Woodfin, W.J.: Sampling with gas bags I: losses of analyte with time.