Enantiomer Separations of Chiral Polychlorinated Biphenyls in Biological Samples

KeyWord:gas chromatography-mass spectrometry  polychlorinated biphenyl  biological sample  chiral  enantiomer  separation

Abstract:

      A method was developed for the separation and determination of 12 chiral polychlorinated biphenyls(PCBs),i.e.CB 45,CB 84,CB 91,CB 95,CB 131£¬CB 132,CB 136,CB 149,CB 171,CB 174,CB 176 and CB 183,in biological samples.The target chemicals were Soxhlet extracted ,cleaned up by gel permeation chromatography and multi-layer silica alumina column,and were further fractioned with a Florisil column.The chiral PCBs were identified and quantified by gas chromatography¨Cmass spectrometry with electron impact ion source(GC-EI/MS).The peak resolutions of these chiral congeners ranged from 0.5 to 2.1.The relative standard deviations of the calculated enantiomeric fractions(EFs) in triplicates were less than 2%.The enantiomers of CBs 84,CB 91 and CB 174 in the standard solutions were separated by two different chiral columns.There was a slight discrepancy in the calculated EFs between the two columns,with relative standard deviations of 1.2%,0.2% and 0.2% for CB 84,CB 91 and CB 174,respectively,suggesting the high degree of accuracy and efficiency of the established method.