COMPOUND-SPECIFIC CHLORINE STABLE ISOTOPE OF VINYL CHLORIDE BY CONTINUOUS FLOW-ISOTOPE RATIO MASS SPECTROMETRY (CF-IRMS)

摘要

A new method for determining compound-specific chlorine stable isotope wasdeveloped for vinyl chloride (VC). The analysis is carried out on a continuous flow-isotoperatio mass spectrometer (CF-IRMS) with special collectors for m/z 64 and 62.The precision of this technique is better than ±0.16‰ (1 σ ) for pure phase gas injectionand head-space SPME injection. The new methodology was tested in a confined sandyaquifer contaminated with VC located near the city of Ferrara, northern Italy. 37 Cl and13 C data on VC showed the contamination is related to the use of VC in the productionof PVC manufactured in the Ferrara region during the 70’s and 80’s. The isotope dataalso showed VC is attenuated by biodegradation along the groundwater flow system.The development of compound-specific isotope analysis (CSIA) for VC offers a newtool for fingerprinting sources and processes that affect VC in groundwater.