Development of a regulatory testing procedure to study the metabolism of pesticides in farmed fish

Abstract

BACKGROUNDDiets used in commercial fish farming use significant proportions of crop‐derived commodities, and it is important to understand the potential for transfer of any pesticide residues on the crop into edible tissues in fish. It is a current requirement in the EU that fish metabolism studies must be performed when a pesticide is used in crops where commodities or processed fractions are fed to farmed fish. Fish metabolism studies in both rainbow trout and common carp have been carried out, following the new working document on the nature of pesticide residues in fish using 14C‐labelled pesticide.RESULTSThe ingestion of experimental diets by rainbow trout and common carp resulted in the uptake and metabolism of the test item, as shown by liquid scintillation counting combined with radio‐thin‐layer chromatography. The metabolite profiles for trout and carp were qualitatively similar regarding the main residue. However, species‐specific differences were found regarding the remaining residue with rainbow trout showing additional metabolites in comparison to carp.CONCLUSIONSMetabolism studies for regulatory purposes can be carried out with both fish species under laboratory conditions. The experimental design reported is suitable for quantifying the transfer of residues to edible tissues and enables characterisation of the chemical nature of residues. © 2015 Fraunhofer Institute for Molecular Biology and Applied Ecology (IME). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A new multiresidue thin layer chromatography–ultraviolet detection method for the rapid determination of six herbicides residue applied as ready mix formulation for rice

“…All six herbicides were resolved and identified in the paddy field sample containing rice grain, straw, and soil (Figure 4) and showed the applicability of the developed TLC‐UV method can be used for the simultaneous determination of six herbicide residues in soil, rice grain, and straw samples. For the identification of biological and environmental samples, TLC is the most widely used separation technique [15, 38. 39].…”

Dietary burden calculations relating to fish metabolism studies

“…Trout ( Oncorhynchus mykiss ) or common carp ( Cyprinus carpio ), which are both important aquaculture species reared for human consumption, are the recommended test species in the working document. Pilot trials with both species to study the metabolism of pesticides in farmed fish were carried out by Schlechtriem et al Based on the findings of the fish metabolism study and the estimated maximum residues which may occur in fish feed (maximum dietary burden), a feeding study may be required for fish, where residues at levels above 0.01 mg kg −1 fresh matter may be reasonably expected in edible tissues. Feeding studies are required to determine the magnitude of residues in products of fish origin in order to assess possible consumer risks arising from ingestion of these products and to establish MRLs for edible fish commodities which still need to be defined.…”