Extraction of chlorinated aliphatic hydrocarbons from groundwater at micromolar concentrations for isotopic analysis of chlorine.
A method is described for near-quantitative extraction of micromolar concentrations of chlorinated aliphatic hydrocarbons (CAHs) from water for determination of chlorine (Cl) isotope ratios. A low pressure, carrier-gas procedure of extraction was proven to be applicable to CH{sub 2}Cl{sub 2}, CCl{sub 4}, C{sub 2}H{sub 2}Cl{sub 2}, and C{sub 2}HCl{sub 3}. The pH of the water was adjusted with NaOH to prevent extraction of CO{sub 2} from air and/or dissolved inorganic carbonate species. Recoveries of CAH samples ({approx}15 {mu}mol), added to and extracted from {approx}340 ml of water, averaged {approx}96%. Average changes in the {delta}{sup 37}Cl values of the CAHs, attributable to the extraction process, were -0.01{+-}0.06{per_thousand}. Significant isotopic fractionation of Cl was measured during partial extraction of C{sub 2}CHCl{sub 3} from water, indicating that near-quantitative extraction is required for reliable stable Cl isotope analysis of CAHs. This method is also suitable for the extraction of dissolved CAH for gas chromatography-combustion-isotope ratio mass spectrometric measurements of hydrogen and carbon.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- EM
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 943045
- Report Number(s):
- ANL/ER/JA-37025
- Journal Information:
- Environ. Pollut., Journal Name: Environ. Pollut. Journal Issue: 3 ; 2001 Vol. 113; ISSN 0269-7491; ISSN ENPOEK
- Country of Publication:
- United States
- Language:
- ENGLISH
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