High-resolution gas chromatographic/high-resolution mass spectrometric analysis of human serum on a whole-weight and lipid basis for 2,3,7,8-tetrachlorodibenzo-p-dioxin

The authors describe an analytical method to measure 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other TCDD isomers in human serum; the method uses a highly specific cleanup procedure and high-resolution gas chromatography/high-resolution mass spectrometry. The 2,3,7,8-TCDD is quantified by the isotope dilution technique with ( super(13)C sub(12))-2,3,7,8-TCDD as the internal standard. Other TCDD isomers are estimated by using published relative response factors. The 1.25 part-per-quadrillion (ppq) limit of detection for 200-g samples is more than adequate for determining 2,3,7,8-TCDD concentrations in human serum specimens. The method is modified for analyzing 50-g and 10-g serum samples. Analytical accuracy is demonstrated by the results obtained in analyzing spiked samples. The method is unaffected by a number of potentially interfering compounds.