ANALYTICAL QUALITY-CONTROL FOR THE DETERMINATION OF POLYCHLOROBIPHENYLS IN ENVIRONMENTAL MATRICES

Analytical quality control procedures for ensuring reliable data in th e determination of PCBs in environmental matrices are described. Sever al extraction procedures of PCBs from sediment samples are critically compared and recovery and reproducibility for PCBs determination in se diment and cod liver oil samples are evaluated. Extraction by 1:1 n-he xane/acetone mixture in an ultrasonic bath and by supercritical fluids generally give a quantitative recovery and a coefficient of variation lower than 15%, while extraction by a Soxhlet system does not give su ch good results and requires much longer extraction times. Certified r eference materials available from three international organizations, n amely the Standards, Measurements and Testing programme of the Europea n Union, the USA National Institute of Standards and Technology and th e National Research Council of Canada were used. Finally, the on-going European Union QUASIMEME programme aimed at improving the analytical quality of marine pollution monitoring measurements of European labora tories is addressed.