Production and certification of ten high-purity polychlorinated biphenyls as reference materials

Abstract

The development by the Community Bureau of Reference of ten polychlorinated biphenyl reference materials of certified purity is reported. The identity of the specially synthesised compounds was mostly confirmed by either nuclear magnetic resonance spectroscopy or X-ray crystallography. Measurements to establish the purity of the ten compounds were carried out in a collaborative certification campaign by 11 European Laboratories. The purity was based on the determination of individual impurities in each compound by applying various well-established measurement techniques. A statistical analysis of the results obtained provided the basis of the certified purity values, which also take account of the presence of trace inorganic impurities.