Performance test of a sorbent tube sampler with respect to analyte loss in collecting biogenic volatile organic compounds

Abstract

The superiority of thermal desorption-gas chromatography (TD-GC) applications is well known for the analysis of biogenic volatile organic compounds (BVOC). Despite the recognition of potential biases associated with sorptive loss reaction, the interaction of reactive BVOC with a sorbent tube (ST) sampler has not been sufficiently investigated. In this study, the extent of such a loss on a sampling device was studied against the sorbent holder materials by comparing stainless steel (SS; main target) and quartz (QZ; reference). To this end, three bed STs (Tenax TA, Carbopack B, and Carbopack X) were prepared using both holding materials (SS vs. QZ). The extent of BVOC loss was then tested for each material against two different phases (liquid and vapor) of ten monoterpenes. Accordingly, the soptive loss on the SS holder ranged from 10 % (vapor) to 20 % (liquid). If a vapor phase BVOC was forced to pass through an empty SS tube, the extent of their loss increased further in a range of 21.1 % (β-P) to 43.5 % (α-T). Likewise, similar loss rates (about 10 % reductions) were also observed when analyzing some environmental samples (pine needle) from the SS holder relative to QZ. Thus, a QZ tube is recommended over a SS tube to avoid sample loss in the collection of BVOC.