Collaborative Study of Soils Spiked with Volatile Organic Compounds

摘要

Vapor fortification is a method of spiking soils with volatile organic compounds(VOCs) that was recently developed for producing materials suitable for performance evaluation and quality assurance/quality control (QA/QC). Using this treatment method, soil subsamples enclosed in heat-sealed glass ampoules were distributed to 16 laboratories for a collaborative round-robin study. The sample sets consisted of duplicates of three different soils. Each soil subsample had been vapor-fortified with the following VOCs: trans-1,2-dichloroethylene (TDCE), trichloroethylene (TCE), benzene (Ben) and toluene (Tol). The laboratories were requested to report analyte concentration estimates for these four analytes and any other detected organic compounds after performing a methanol extraction, purge-and-trap gas chromatography, mass spectrometry analysis. The results from the 12 laboratories that met all of the design criteria produced a range of relative standard deviations from 8.5 to 28.2%, with a pooled standard deviation of less than 13%. The smallest range of consensus values was for Ben (pooled RSD = 9.0%), while the determination of TDCE showed the greatest overall uncertainty (pooled RSD = 20.3%). This round-robin effort confirmed that the use of vapor-fortified soils sealed in glass ampoules is a precise way of preparing and storing VOC-spiked soil subsamples. (AN).