The storage stability of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags

Abstract

In this study, the sorptive loss properties of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags were investigated as a function of storage duration. To this end, the relative recovery of gas phase standards of BVOCs, obtained via vaporization of liquid phase standards, was computed by calibrating their standards (response factors: RF) represnting each phase. Accordingly, the results indicated either slight loss (-5.59% (isoprene), -2.39% (camphene), -1.69% ((R)-(+)-limonene), -0.88% (p-cymene)) or gain (1.47% (gamma-terpinene), 2.27% (alpha-terpinene), 2.63% (alpha-phellandrene), 2.73% ((+)-3-carene), 3.93% ((+)-beta-pinene), and 5.98% ((+)-alpha-pinene)). Through comparison of the calibration results across storage time, the temporal stability of BVOCs was assessed. Longer BVOC storage time in polyester aluminum (PEA) bags lowered the relative recovery of BVOCs. The relative loss of BVOCs, if calculated in terms of mean bag standard RF ratios (relative to liquid standard) across elapsed time, decreased systematically: 0.99 +/- 0.05 (0 h), 0.88 +/- 0.06 (24 h), 0.66 +/- 0.11 (72 h), and 0.62 +/- 0.14 (120 h). It is thus recommended to complete the analysis of BVOC in PEA bags within 24 h of sample acquisition. As such, it is important to apply appropriate sampling approaches with a proper storage plan when measuring ambient BVOCs collected by bag sampling methods.