Two-dimensional gas chromatography coupled to triple quadrupole mass spectrometry for the unambiguous determination of atropisomeric polychlorinated biphenyls in environmental samples

Two-dimensional gas chromatography coupled to triple quadrupole mass spectrometry (GC–GC–MS–MS) is presented as a robust, selective and sensitive method for the accurate quantification of enantiomeric fractions (EFs) of atropisomeric polychlorinated biphenyls (PCBs) in a range of environmental matrices. The method was subjected to a set of quality control and validation experiments. EF precision of the atropisomers 95, 149, 132, and 174 ranged from 0.7 to 1.4% in soil samples. Quantified amounts of these congeners in soil and compost samples (59 < n < 100) were on average within 3–26% of the numbers gathered with conventional (achiral) bench top GC–MS. However, significant deviations were observed between EFs obtained by GC–GC–MS–MS and those by GC–GC–MS, GC–MS–MS, and GC–MS. The method was successfully applied to a variety of sample types, such as soil, air, herring, human milk, and, for the first time, compost. EFs in soils are shown to vary with land use and correlations with soil pH were observed. EFs in compost samples were mostly close to, or racemic.