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

Peak assignment and quantification of PCBs in environmental samples is a ti me-consuming and costly process, and the analysis of atropisomeric PCBs is even more laborious and costly due to the elaborate analytical work involve d. GC X GC can solve some of the problems entailed by increasing congener r esolution and instrument sensitivity. In this study. a comprehensive two-di mensional gas chromatography (GC X GC) system was utilized with a combinati on of a permethylated beta -cyclodextrin column in the first dimension and a liquid crystal column in the second dimension. Using this system, in a si ngle 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 p artially 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 t he highest resolution. Furthermore, the congers that (partially) coelute wi th 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 coul d be separated from significant interfering compounds in a single GC X GC r un. (C) 2001 John Wiley & Sons. Inc.