Reports on the results of the seventh intercalibration exercise on trace metals in biota (Part 1)

Three marine biological tissue samples (lobster hepatopancreas, scallops and plaice) were distributed to 57 ICES laboratories, 51 of which submitted results, Values were collated for the six metals, copper, zinc, arsenic, cadmium, mercury and lead, Most iaboratories perform well for copper, zinc and cadmium, although there is an indication of a possible matrix problem for copper in plaice. Most of those that analyze for mercury are able to do so even at low (0,06 mg/kg) concentrations. Many laboratories have problems with lead, even at the 5 mg/kg

level, and with low level cadmium (0,06 mg/kg), Only about 40 percent of the respondents analyzed the materials for As, an element which appears to present problems, The distribution of results is poor (21% RSD) at the 25 mg/kg level and deteriorates further (35% RSD) at 5 mg/kg, Results for chromium, manganese, iron, cobalt, nickel and selenium are also tabulated.