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Compound‐specific hydrogen isotope analysis of 1,2‐dichloroethane: potential for delineating source and fate of chlorinated hydrocarbon contaminants in groundwater
Author(s) -
Chartrand Michelle M. G.,
Hirschorn Sarah K.,
LacrampeCouloume Georges,
Sherwood Lollar Barbara
Publication year - 2007
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.3026
Subject(s) - chemistry , mass spectrometry , chlorine , 1,2 dichloroethane , groundwater , gas chromatography , detection limit , isotope analysis , hydrocarbon , isotope , analytical chemistry (journal) , environmental remediation , contamination , chromatography , environmental chemistry , organic chemistry , physics , geotechnical engineering , quantum mechanics , engineering , biology , catalysis , ecology
A Delta Plus XL continuous flow gas chromatography/high‐temperature conversion‐isotope ratio mass spectrometer system (GC‐TC‐IRMS) with a liquid nitrogen trap installed at the end of the micropyrolysis oven was used to measure hydrogen isotope ( δ 2 H) values of 1,2‐dichloroethane (1,2‐DCA). The 1,2‐DCA δ 2 H values were within uncertainty of the δ 2 H value for the same 1,2‐DCA analyzed using off‐line sample preparation and conventional dual inlet mass spectrometry, verifying that this system can accurately measure 1,2‐DCA δ 2 H values. After 71 reproducible and accurate 1,2‐DCA δ 2 H measurements had been obtained, the standard deviation on the mean of the cumulative 1,2‐DCA δ 2 H measurements was greater than ±5‰. The cumulative load of chlorine at this point was ∼5.5 × 10 −6 moles, which may be the limit to the quantity of chlorine that can be input before the reproducibility of 1,2‐DCA δ 2 H measurements is compromised. This study is the first to our knowledge to demonstrate a method for obtaining accurate and reproducible compound‐specific δ 2 H values for chlorinated hydrocarbons at dissolved concentrations typical of field conditions. Paired δ 2 H and δ 13 C values suggest that dual parameter isotopic measurements can distinguish between different contaminant sources, as well as providing additional constraints on degradation pathways and contaminant remediation. Copyright © 2007 John Wiley & Sons, Ltd.