CONVERSION OF CHLORINATED VOLATILE ORGANIC-COMPOUNDS TO CARBON-DIOXIDE AND METHYL-CHLORIDE FOR ISOTOPIC ANALYSIS OF CARBON AND CHLORINE

A nonaqueous, high-temperature method is described for converting micr omole quantities of chlorinated volatile organic compounds to CO2 and CH3Cl for C and Cl isotope ratio determinations. This method provides an improved analytical approach for using C and CI isotope ratios in s tudies of the biodegradation of chlorinated volatile organic compounds in the environment. Conversion of reagent CH3Cl to CO2 + CuCl and the n conversion of the CuCl back to CH3Cl by the present method gives typ ical yields of 99 +/- 1% for CO2 and 91 +/- 1% for CH3Cl, both product s of >99% purity. An offset of -0.23 +/- 0.05 parts per thousand is ob served between the Cl-37/Cl-35 ratios of product and initial CH3Cl. Pr ecision of the isotopic ratio measurements is better than +/- 0.1 part s per thousand for a variety of chlorinated volatile organic compounds .