The effect of stirring on purge-and-trap extraction of VOCs in soil

摘要

Water and preservative were added to aliquots of an organic soil spiked with a standard volatile organic compound (VOC) mixture. These analytes were extracted from the soil matrix using a purge-and-trap technique, SW-846 EPA (Environmental Protection Agency) Method 5035, and then separated, identified, and quantitated by gas chromatography/mass spectrometry (GC/MS) using the conditions described in SW-846 EPA Method 8260. Recoveries of VOCs from soil samples that were stirred for two minutes prior to and during the purge were compared with those that were not stirred during the purge step. It was shown that stirring the soil sample gave improved extraction efficiencies and slightly larger relative standard deviations. [References: 6]