Congener-specific concentrations and carbon stable isotope ratios (δ13C) of two technical toxaphene products (Toxaphene® and Melipax®)

Identical amounts of Melipax or Toxaphene were combusted to CO2 in an element analyzer and their δ13C values were determined relative to the international standard Vienna PeeDee belemnite (VPDB). The mean δ13C values of both products varied by 2.8% (determined at two different locations) which is roughly one order of magnitude more than the precision obtained in repetitive analyses of the individual products. Thus, both investigated products could be unequivocally distinguished by stable isotope ratio mass spectrometry (IRMS). IRMS analyses may thus be a suitable tool for tracing back toxaphene residues in environmental and food samples to the one or both of the products.