PRACTICAL STEPS TO IMPROVE THE QUALITY-CONTROL OF THE CHROMATOGRAPHY FOR CHLOROBIPHENYL AND ORGANOCHLORINE PESTICIDE ANALYSIS

A study of the variability of the final determination of chlorinated b iphenyls (CBs) and organochlorine pesticides (OCPs) using a gas chroma tograph with an electron capture detector (GC-ECD) was carried out usi ng both archived data, and data obtained following the optimization an d validation of the GC-ECD. The precision and bias of the laboratory's historical data lay outside the recommended limits of the ICES and QU ASIMEME intercomparison exercises, and for those following GC optimiza tion the repeatability was greatly improved. New control limits were s et to international guidelines. The steps taken to achieve greater pre cision and accuracy from a determination are detailed.