title: Quantification of achiral and chiral methylsulfonyl polychlorinated biphenyl metabolites by column-switching liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry.
abstract: An enantioselective heart-cut column-switching liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry method was developed for the analysis of 25 methylsulfonyl polychlorinated biphenyl metabolites in tissue extracts. Use of a pyrenyl-ethyl silica column in the first dimension enabled separation of all but two pairs of isobaric analytes. Enantioseparation was achieved for 9 out of the 10 atropisomeric analytes using a Chiralpak AD-H amylose-based column within 93 min, resulting in greater chromatographic resolution of enantioseparation over shorter analysis time by up to a factor of three, compared to previous one-dimensional and multi-dimensional gas chromatography-based methods. Precision for concentration and enantiomer fraction measurements was within 11% and 3% relative standard deviation, respectively. Limits of detection ranged from 0.01 to 1.73 ng on-column. Meta-congeners had poorer sensitivity (i.e., ng on-column), consistent with existing gas chromatography-based methods. Despite this limitation, the method was successfully applied to the analysis of Greenland sledge dog adipose tissue extracts, which had highly non-racemic residues of 4-methylsulfonyl-2,2',3,5',6-pentachlorobiphenyl and 4'-methylsulfonyl-2,2',3,3',4,6'-hexachlorobiphenyl, consistent with past reports in Arctic mammals.
authors.affiliation: University of Alberta, Department of Chemistry, Edmonton, Alberta T6G 2G2, Canada.
authors.forename: Victoria I
authors.initials: VI
authors.lastname: Cooper
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.forename: Rune
authors.initials: R
authors.lastname: Dietz
authors.forename: Christian
authors.initials: C
authors.lastname: Sonne
authors.forename: Charles S
authors.initials: CS
authors.lastname: Wong
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D004285:Dogs; D008297:Male; D015394:Molecular Structure; D011078:Polychlorinated Biphenyls / Q000737:chemistry* / Q000378:metabolism; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D011078:Polychlorinated Biphenyls