Determination of residues of carbofuran and its metabolites in tissues of buffaloes and ducks

Abstract

A research work on the determination of residues of carbofuran and its metabolites in tissues of buffaloes (Bubalus bubalis) and ducks (Anas platyrhynchos) was under taken. The objectives were to develop and standardise a suitable simple method of extraction of residues of carbofuran and its metabolite from meat, liver, kidney and fat of buffaloes and ducks for reversed phase HPLC analysis and to apply this method for further screening of animal tissues for monitoring these residues Fifteen samples of each tissue of buffaloes and ducks were randomly collected from different lots of slaughtered animals in Kerala. Different solvents, viz., acetonitrile (ACN), acetone, methanol, hexane and 2-propanol were used for the extraction of carbofuran residues and its metabolite from tissues. The extracted samples were cleaned up by liquid-liquid partitioning for HPLC analysis using Schimadzu LC-10 AVP series with UV/VIS detector at 211 nm in a mobile phase of acetonitrile (35): water (65). Certified standard references of carbofuran and its metabolites, viz., 3-hydroxy carbofuran, 3-keto carbofuran, 3-hydroxy 7-phenol carbofuran, 3-keto 7-phenol carbofuran and carbofuran phenol were analysed in HPLC to identify the chromatogram peaks of respective compounds. Excellent linearity was observed for carbofuran and 3-hydroxy carbofuran at 1, 10 and 100 ppm. Based on the highest percentage of recovery, ACN was chosen as the best solvent for extraction of residues from meat, liver and kidney and hexane for fat. This solvent system was applied for the extraction of residues in a further HPLC residue monitoring programme in the tissues of buffaloes and ducks. In buffalo meat, liver, kidney and fat the residues of carbofuran and its metabolites could not be detected and hence denoted as below detection limit (BDL). Residues could not be detected in all duck tissue samples, except in one sample, wherein 3-hydroxy carbofuran was detected at 2 ppm and 0.9 ppm in meat and kidney, respectively which is above the MRL. An appropriate method is developed for the screening of animal tissues to detect the presence of residues of carbofuran and its metabolites. This would enable in monitoring and surveillance of residues of carbofuran in animal tissues, hazard analysis and determining the critical control points.