Comparison of various adsorbents for long-term diffusive sampling of volatile organic compounds

Abstract

The relative performances of diffusive samplers packed with Tenax TA, Chromosorb 106 and Carbotrap for the long-term diffusive sampling of several typical volatile organic compounds were compared. In order to measure the magnitudes of the decreases in mass uptakes in a real long-term diffusive sampling situation, the results for 7 and 14 d sampling periods were compared with the sum of consecutive 1 d diffusive sampling results, performed in parallel for the same period of time. The results of this study gives information about the magnitudes of the decreases in mass uptakes in a real sampling situation and show the limitations of the adsorbents tested for the sampling of volatile organic compounds from different classes such as acetone and dichloromethane as compounds with a functional group, toluene as an example of aromatic compounds and pentane, hexane, nonane, decane and undecane as examples of straight chain hydrocarbons (C₅–C₁₁). It was shown that the data obtained from long-term diffusive sampling are subject to significant error, particularly for low boiling compounds. Chromosorb 106 could be the adsorbent of choice for this sampling situation, as it gives the highest percentage of masses (ng) collected for longer exposure periods relative to the sum of the masses (ng) collected over each exposure period among the other adsorbents tested.