Study On Simultaneous Determination Method For Azole Class Antifungal Agents Residues In Chicken

As the members of the azole class antifungal agents, enilconazole, parconazole, thiabendazole and 5-hydroxythiabendazole are widely used in the course of fungal infection in veterinary. The toxic effects could cause health risk for consumers through the residues in foods from animal origin such as meat, milk and egg. Multiple using of these antifungal agents may increase the health risk. Therefore, it is very necessary to monitor and control the residual drugs in food. An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of residues of thiabenazole, 5-hydroxythiabenazole, enilconazole, parconazole in the food of chicken including liver, muscle and egg. Homogenized samples were extracted by acetonitrile, cleaned up and concentrated with the Oasis MCX solid phase extraction (SPE) cartridge. The separation of the analytes was performed by liquid chromatography with an UPLCTM BEH C18 column, coupled with electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS/MS) operating in positive multiple-reaction mode (MRM). Good linearity was obtained at the concentrations of 0.01~100μg/kg for thiabendazole, and 0.1-100μg/kg for other drugs. The regression coefficients (r~2) for all the calibration curves were >0.99. Average recoveries of the analytes in chicken liver, muscle and egg at six fortification levels (0.2~200 ng/kg) were in the range 93-119% with acceptable coefficients of variation (<14%, n=6).Then the distribution and depletion of thiabendazole and its metabolites 5-hydrothiabendazole residues in the hens tissues was studied. Laying hens were given thiabendazole for 5 consecutive days (100mg per hen daily) and then the hens were sacrificed at 1 day, 3 days, 5 days and 7days after the end of treatment. Eggs, liver, muscle, fat and heart tissues were collected and homogenized. The major residue found in the edibles matrix was 5-hydroxythiabendazole, with significantly higher concentrations than thiabendazole. Egg samples present the large majority of the drug residues. For the tissue samples, thiabendazole and 5-hydrothiabendazole residue levels followed the order of liver > heart > muscle > fat.Therefor, the objective of this work is to develop a method for determination of enilconazole, parconazole, thiabenazole and metabolites in chicken tissues, including liver, muscle and egg by a single multi-residue method. Then the residues of thiabendazole and its metabolites 5-hydrothiabendazole in the hens tissues including liver, muscle. heart, fat, as well as in eggs were studied. Speculating the withdrawal period of thiabenazole could give a basis for clinical medicine and slaughter management.