Assessment of ionic liquid stationary phases for the determination of polychlorinated biphenyls, organochlorine pesticides and polybrominated diphenyl ethers.

Five ionic liquid stationary phases were tested for the gas chromatographic (GC) analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In comparison with a non-polar DB5MS stationary phase, which is normally used in single-column GC for these compounds, all phases tested provided a different elution pattern. Mono-ortho substituted PCBs showed longer retention times, whereas di-ortho PCB congeners eluted earlier. These different patterns provide a potential for use of these columns for single-column PCB analysis, but in particular for use in comprehensive two-dimensional GC (GC×GC). The SLB-IL111 phase showed the most striking differences in elution of PCBs compared to DB5MS. The analysis of OCPs was hindered by adsorption and on-column degradation with most of the phases tested. Additional experiments with polybrominated diphenylethers (PBDEs) also revealed serious degradation of most of the congeners. Only the SLB-IL60 column showed a better performance for OCPs, in combination with a relatively low bleeding.