USING C-14-LABELED RADIOCHEMICALS CAN CAUSE EXPERIMENTAL ERROR IN STUDIES OF THE BEHAVIOR OF VOLATILE ORGANIC-COMPOUNDS

This study demonstrates that using C-14-labeled radiochemicals can cause potential experimental artifacts and error in studies of the behavior of volatile organic compounds (VOCs), such as trichloroethylene (TCE) and tetrachloroethylene (PCE). Results indicated that the volatilization rates of C-14-labeled TCE and PCE (analyzed by C-14 radioactivity) were much lower than those of unlabeled TCE and PCE (analyzed by GC). These observations are attributed to (1) the presence of impurities that may be nonvolatile or less volatile than the target organic compound and (2) a possible isotopic discrimination between C-14-labeled and unlabeled VOCs. It is therefore suggested that caution be used in using radiochemicals in studies of VOC behavior in environmental media and in interpreting experimental data.