Determination of 20 coccidiostats in egg and avian muscle tissue using ultra high performance liquid chromatography-tandem mass spectrometry

A quantitative, comprehensive multiresidue method which includes 20 coccidiostat residues has been developed. The method described uses a simple one-step liquid extraction with acetonitrile to isolate analytes from both the polyether ionophore and chemical classes of coccidiostats. Subsequent to a further concentration step, samples were analysed via UHPLC-MS/MS. The method was validated according to the Commission Decision 2002/657/EEC in egg and avian muscle. The method permitted quantitative confirmation for 13 compounds below target concentrations, and screening for a further 7 compounds. Within-laboratory repeatability gave accuracy values in the range of 68-129%, while reproducibility ranged between 75 and 123%. Calibration ranges were typically 1-50 mu g kg(-1), although higher ranges were used for dinitrocarbanilide, imidocarb and toltrazuril residues. A regression coefficient (R-2) value of greater than 0.98 was obtained for all analytes. Precision results ranged from 2.3 to 19.7% CV for egg and from 2.6 to 23.6% CV in muscle. CC alpha was in the range from 1.13 mu g kg(-1) (clopidol) to 179 mu g kg(-1) (lasalocid) in egg. In muscle, CCa ranged from 2.25 mu g kg(-1) (aprinocid) to 4579 mu g kg(-1) (dinitrocarbanilide). CC beta was from 1.29 mu g kg(-1) (clopidol) to 209 mu g kg(-1) (lasalocid) in egg, and 2.58 mu g kg(-1) (arprinocid) to 6060 mu g kg(-1) (dinitrocarbanilide) in muscle. Limits of quantification were 1 mu g kg(-1) for all compounds, except imidocarb and dinitrocarbanilide (10 mu g kg(-1)), and toltrazuril and metabolites (50 mu g kg(-1)). (C) 2012 Elsevier B.V. All rights reserved.