Gas chromatography–triple quadrupole mass spectrometry analysis of dioxins in soil

Abstract

The applicability of gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) for determination of dioxins in soil was investigated. The analytical method was validated based on US Environmental Protection Agency (EPA) Method 1613 and European Union (EU) Regulation No. 709/2014 for selectivity, linearity of sensitivity, and instrumental limits of quantification (iLOQs). Method development commenced with determination of retention times for 17 native polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and selection of characteristic ions from GC-MS/MS spectra. The linearity was measured using 1613 standard solutions (CS1-CS5) containing 0.5 to 200 ng/mL tetrachlorodibenzo-p-dioxin/furan (TCDD/F) congeners, 2.5 to 1000 ng/mL pentachlorodibenzo-p-dioxin/furan (PeCDD/F) to heptachlorodibenzo-p-dioxin/furan (HpCDD/F) congeners, and 20 to 2000 ng/mL octachlorodibenzo-p-dioxin/furan (OCDD/F) congeners. The correlation coefficient (R 2) values ranged between 0.9990 and 0.9999, and the iLOQ values ranged from 0.052 to 0.350 pg/μL for TCDD/F congeners, with a relative standard deviation of 2.7-9.6%. The entire analytical method was verified by analysis of certified reference materials (BCR-529 and BCR-530), and the recoveries were 71.79-103.87% and 81.50-103.12%, respectively. Thus, the GC-MS/MS system provides an alternative to GC-high-resolution MS for the simultaneous determination of TCDD/F congeners in soil.