Determination of single PCB congeners in fish by on-line LC-GC

An on‐line coupled LC‐GC technique was applied to the analysis of polychlorobiphenyls (PCBs) in Baltic herring. The liquid chromatographic (LC) and gas chromatographic (GC) instruments were coupled with a loop‐type interface and concurrent solvent evaporation was used in transferring the sample to the GC. A cyano phase with hexane as eluent was used for the LC separation and an NB‐54 column was used for the GC separation. On‐line LC‐GC is a good alternative to GC for the analysis of PCB compounds in biological material. The number of sample propurification steps is fewer and, the risks of sample contamination and loss are reduced.