Determination of toxaphene in biological samples using high resolution GC coupled with ion trap MS/MS

Toxaphene remains as a pollutant of global concern because of its persistence in the environment. Its complex combination of congeners and the lack of individual standards makes accurate measurement of toxaphene residues in environmental samples a challenge. We have developed a novel method to measure toxaphene in environmental samples using ion trap MS/MS. Adequate sensitivity for analysis of biological samples such as fish and marine mammal blubbers were achieved (around 0.02 ppb to 0.06 ppb for individual congeners and 5.6 ppb for toxaphene mixtures). Accuracy was demonstrated by good recoveries of spiked toxaphene in corn oil samples (102% for toxaphene congeners at 4 ppb and 96% for toxaphene mixture at 139 ppb level). Results of analysis of toxaphene in cod liver oil (NIST SRM 1588) using the MS/MS method compared favorably with the median round robin interlaboratory data. The major advantage of the ion trap MS/MS over the existing methods; electron capture negative ionization mass spectrometer or electron capture detector, is its excellent selectivity. Interference from other organochlorines can virtually be eliminated. Therefore, the developed MS/MS method can be used as a reliable alternative to high resolution mass spectrometer for measurement of toxaphene in environmental samples with relatively low cost instrumentation.