title: Determining indicator toxaphene congeners in soil using comprehensive two-dimensional gas chromatography-tandem mass spectrometry.
abstract: Toxaphene, which is a broad spectrum chlorinated pesticide, is a complex mixture of several hundred congeners, mainly polychlorinated bornanes. Quantifying toxaphene in environmental samples is difficult because of its complexity, and because each congener has a different response factor. Toxaphene chromatograms acquired using one-dimensional gas chromatography (1DGC) show that this technique cannot be used to separate all of the toxaphene congeners. We developed and validated a sensitive and quantitative method for determining three indicator toxaphene congeners in soil using an isotope dilution/comprehensive two-dimensional gas chromatography-tandem mass spectrometry (GC × GC-MS). The samples were extracted using accelerated solvent extraction, and then the extracts were purified using silica gel columns. (13)C₁₀-labeled Parlar 26 and 50 were used as internal standards and (13)C₁₀-labeled Parlar 62 was used as an injection standard. The sample extraction and purification treatments and the GC × GC-MS parameters were optimized. Subsequently the samples were determined by GC × GC-MS. The limits of detection for Parlar 26, 50, and 62 were 0.6 pg/g, 0.4 pg/g, and 1.0 pg/g (S/N=3), respectively, and the calibration curves had good linear correlations between 50 and 1000 μg/L (r(2)>0.99). Comprehensive two-dimensional GC gave substantial improvements over one-dimensional GC in the toxaphene analysis. We analyzed soil samples containing trace quantities of toxaphene to demonstrate that the developed method could be used to analyze toxaphene in environmental samples.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Agricultural University of Hebei, Baoding 071000, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhu
authors.forename: Lirong
authors.initials: L
authors.lastname: Gao
authors.forename: Minghui
authors.initials: M
authors.lastname: Zheng
authors.forename: Huimin
authors.initials: H
authors.lastname: Liu
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: Lidan
authors.initials: L
authors.lastname: Liu
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001892:Camphanes / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014112:Toxaphene / Q000032:analysis*
chemical_list: D001892:Camphanes; D007306:Insecticides; D012987:Soil; D012989:Soil Pollutants; D014112:Toxaphene
keywords: Comprehensive two-dimensional gas chromatography; GC×GC; Indicator toxaphene congeners; Soil; Tandem mass spectrometry