Abstract
Studies were made on an analytical method for determining residues of oxadiazon herbicide in fish and shellfish, consumption of which has recently increased, and the levels of residues in crucian carps were investigated. In order to eliminate interference, particularly of PCBs and organochlorine insecticides, which had contaminated freshwater and marine fishes at high levels, conditions of Florisil column chromatography and ECD gas chromatography were examined and one method was found for routine analysis of oxadiazon where a recovery of 96.0% could be obtained. When the flesh of crucian carps, collected in Lake Kojima 2 months, 4 months and 9 months after application of oxadiazon, was analyzed by this method, 0.442ppm, 0.046ppm and 0.017ppm were detected, respectively. This suggests the possibility that oxadiazon may have a strong persistence in fish. Identification was carried out by means of mass spectrometry and mass chromatography.
