DETERMINATION OF METHYL, ETHYL, PHENYL AND TOTAL MERCURY IN NECKAR RIVER FISH

Methyl-, ethyl- and phenyl mercury, total mercury and fat content were determined in fish fillet of the five different fish species: eel, perch, roach, chub and barbel. The organo mercury compounds were extracted according to a modified Westoo method and determined by using HPLC-cold vapour atomic absorption spectrometrie. Total mercury was determined according to EPA/AOAC. Total mercury in fish tissue varied between 16 and 812 mu g/kg, methyl mercury between 10 and 770 mu g/kg. It was found that at least 83 % of total mercury is present as methyl mercury. Only a barbel exceeded the German maximum acceptable residue limit (500 mu g/kg) with 812 mu g/kg total mercury.