title: Rapid and simultaneous determination of polychlorinated biphenyls and their main metabolites (hydroxylated and methyl sulfonyl) by gas chromatography coupled to mass spectrometry: comparison of different ionisation modes.
abstract: Instrumental methods based on gas chromatography coupled to mass spectrometry (GC-MS) have been developed and compared using two different MS ionisation modes, electron impact (EI) and electron capture negative ionisation (ECNI), for the fast, quantitative and simultaneous determination of polychlorinated biphenyls (PCBs) and their main metabolites (hydroxylated PCBs, OH-PCBs, and methyl sulfone PCBs, MeSO2-PCBs). Parameters affecting chromatographic separation and MS detection were evaluated in order to achieve the highest selectivity and sensitivity for both operation modes. The analytical characteristics of the developed methods were studied and compared in terms of linear range, limits of detection (LODs), limits of quantification (LOQs), and instrumental precision (repeatability and intermediate precision). Both ionisation methods showed similar precision, being relative standard deviations (RSD, %) lower than 9% and 14% for repeatability and intermediate precision, respectively. However, better LODs (from 0.01 to 0.14 pg injected for the three families of congeners studied) were achieved using ECNI-MS as ionisation mode. The suitability of the developed method was demonstrated through their application to fish liver oil samples.
authors.affiliation: Department of Instrumental Analysis and Environmental Chemistry, Institute of General Organic Chemistry, CSIC, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Castro-Puyana
authors.forename: L
authors.initials: L
authors.lastname: Herrero
authors.forename: M J
authors.initials: MJ
authors.lastname: González
authors.forename: B
authors.initials: B
authors.lastname: Gómara
mesh_terms: D004121:Dimethyl Sulfoxide / Q000032:analysis; D005395:Fish Oils / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006900:Hydroxylation; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D013450:Sulfones / Q000032:analysis; D013997:Time Factors
chemical_list: D005395:Fish Oils; D013450:Sulfones; C025910:dimethyl sulfone; D011078:Polychlorinated Biphenyls; D004121:Dimethyl Sulfoxide
keywords: Electron capture negative ionisation; Electron impact; Gas chromatography; Mass spectrometry; Metabolites; Polychlorinated biphenyls