A new method for the extraction of chlorinated solvents (CSs) from porewater with dimethylacetamide (DMA) used as a solvent and the determination of δ¹³C by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) with solid-phase microextraction (SPME) are presented. This method was used for the determination of δ¹³C of chloroethenes and chloromethanes. The extraction of the CSs from porewater with DMA led to a minimal loss of mass of solvent and chlorinated compounds. The accuracy of the method was verified with the analysis of the pure injected compounds using elemental analyzer—isotope ratio mass spectrometry (EA-IRMS). It has been effectively applied in a study area in saturated soil samples of a pollutant source zone of perchloroethylene (PCE) and trichloroethylene (TCE). The limit of quantification of the new method was 0.034 μg/g for PCE and TCE for 10–20 g of soil sample. This new method allows for compound-specific isotope analysis of CSs in porewater, which can be beneficial in sites where the identification of contamination sources and the behavior of the contaminants are not clear.

中文翻译：

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一种测定孔隙水中氯化溶剂化合物特定碳同位素的新方法

一种以二甲基乙酰胺 (DMA) 为溶剂从孔隙水中提取氯化溶剂 (CSs) 的新方法，并通过气相色谱-同位素比质谱 (GC-IRMS) 和固相微萃取 (SPME)测定 δ ¹³ C ) 呈现。本方法用于测定δ ¹³C 氯乙烯和氯甲烷。使用 DMA 从孔隙水中提取 CSs 导致溶剂和氯化化合物的质量损失最小。该方法的准确性通过使用元素分析仪 - 同位素比质谱 (EA-IRMS) 对纯进样化合物的分析进行了验证。已在研究区的四氯乙烯（PCE）和三氯乙烯（TCE）污染源区饱和土壤样品中得到有效应用。对于 10–20 g 土壤样品，新方法的定量限为 0.034 μg/g 的 PCE 和 TCE。这种新方法允许对孔隙水中的 CSs 进行化合物特定的同位素分析，这在污染源的识别和污染物的行为尚不清楚的地点是有益的。