Comprehensive two-dimensional gas chromatography (GC x GC) of atropisomeric PCBs, combining a narrow bore β-cyclodextrin column and a liquid crystal column

Peak assignment and quantification of PCBs in environmental samples is a time-consuming and costly process, and the analysis of atropisomeric PCBs is even more laborious and costly due to the elaborate analytical work involved. GC X GC can solve some of the problems entailed by increasing congener resolution and instrument sensitivity. In this study. a comprehensive two-dimensional gas chromatography (GC X GC) system was utilized with a combination of a permethylated beta -cyclodextrin column in the first dimension and a liquid crystal column in the second dimension. Using this system, in a single GC X GC run six out of nine studied atropisomeric PCBs (PCBs 91, 132, 135. 136, 149, and 176) can be resolved, and two (PCBs 84 and 174) can be partially separated from coeluting congeners in a mixture of 144 congeners (the most abundant congeners in technical PCBs). The chiral resolution (Rs) of the enantiomeric pairs ranged between 0.6 and 2.0, with PCB 132 having the highest resolution. Furthermore, the congers that (partially) coelute with enantiomers of PCBs 84, 95, and 174 have low abundance in technical PCB as well as in environmental samples. Thus, all of the nine target PCBs could be separated from significant interfering compounds in a single GC X GC run. (C) 2001 John Wiley & Sons. Inc.