Interlaboratory studies of the determination of selected chlorobiphenyl congeners with capillary gas chromatography using splitless- and on-column injection techniques

The Community Bureau of Reference has organized a collaborative interlaboratory project to improve the analytical protocol for some specific chlorobiphenyls (CBs) within the European Community (EC). A series of test procedures were prescribed to optimize the gas chromatographic conditions for splitless and on-column injection, which substantially improved the quality of data. Important parameters included the initial column and injector temperatures and the choice of the polarity of the stationary phase. In a study with cleaned eel-fat extracts, coefficients of variation for reproducibility CV(R) ranging from 11 to 24% at the 0.04–0.3 mg/kg level per CB congener were obtained. No significant difference could be found between splitless- and on-column injection.