Interlaboratory Study on the Analysis of Chlorobiphenyl Congeners

Abstract

Abstract An intercompanson exercise on the determination of individual chlorobiphenyls (CBs) in marine media was organized by the International Council for Exploration of the Sea, the Intergovernmental Oceanographic Commission, and the Oslo and Paris Commissions. Sixty-two laboratories from 16 countries participated in the first part of this exercise, which consisted of determining 10 CBs in a standard solution. Considerable emphasis was placed on optimization of the gas chromatographic analysis, which has led to better agreement than former intercalibration exercises on CB analysis. Standard errors of 1.10-1.12 for the reproducibility were obtained for all CBs, except CB 52 for a group of 47 laboratories. It was demonstrated that the linear range of the electron capture detector was restricted to a factor of 5 in the concentration range 15-750 pg. About half of the participants used calibration solutions with CB concentrations outside the linear range. More than half of the participants had difficulties in separating the peaks of CB 28 and CB 31. Results based on peak heights showed better reproducibility than results based on peak areas