| Coccidiostat(CCs)are used for the prevention,treatment and diagnosis of coccidiosis in livestock and poultry,ensuring the safety of food quantity and animal health in China.However,the animal food with CCs residues would directly or indirectly lead to potential food safety problems through the food chain,such as acute or chronic poisoning and fetal anomaly.As a result,relevant departments in China have successively formulated and updated CCs banned lists or maximum residue limits in related foods.It is an important link to ensure food safety by carrying out the analysis of the elimination rule and establishing its residue detection method.At present,there are few researches on the elimination of CCs in eggs and analysis methods of various residues.Hence,this study aimed to establish an Ultra high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)method for the detection of 26 kinds of CCs in eggs,and to use this method to carry out a preliminary exploration of the distribution elimination rules of 4 kinds of CCs in egg yolk and egg white.Details as follows:The molecular ion information declustering voltage and collision energy of 26 CCs were optimized to establish a mass spectrometry acquisition method.The sample was chelated with 0.5 m L of EDTA solution(0.2mol/L),extracted with Acetonitrile methanol water and salted out with 2.0 g of sodium chloride.The residue was repeatedly extracted.The extract was purified by Qu ECh ERS beast residual salt bag and centrifuged after water elimination.Afterwards,take 3m L of LPAS for purification,blow it to dryness with nitrogen.It was reconstituted with 1 m L of 50%methanol water,which have passed through a millipore filter.Then,keep in positive and negative ionization mode using an electrospray ionization source with the multiple reaction monitoring mode(MRM).Moreover,The Kinetex(?)F5chromatographic column was adopted.Gradient elution was performed with 0.1%formic acid+5mmol aqueous ammonium acetate and methanol as mobile phase,and the quantification was carried out by blank matrix matching curve external standard method.4 kinds of CCs were administered in different multiples of the recommended doses as a mixture or drinking water.Eggs were collected during the medication and the withdrawal period.In the meantime,the yolk and egg white were separated.The distribution elimination rule of four kinds of CCs in egg white and egg yolk was measured by this test method,and mutual verification was carried out in combination with SN/T 2444-2010 commodity inspection standard and Ministry of Agriculture Notice No.1025 and-23-2008.The method has demonstrated a good linear relationship in the concentration range of 5～400 ng/m L,the correlation coefficient R2 was greater than 0.99,the average recovery rate of 26 kinds of CCs was 94.70%～104.86%,and the intra-assay and inter-assay precision was 1.71 % ～17.72%,the detection limit was 0.01～2.7μk/kg,and the quantification limit was 0.1～8.0 μk/kg.At the same time,the accuracy,repeatability as well as sensitivity of the method significantly meet the requirements of laboratory inspection quality control.Three kinds of CCs were mainly distributed in egg yolk,and one kind of yolk was equally distributed in egg white.The elimination time of egg yolk residue was longer than that of egg white.Distribution ratio of egg groups with different concentrations in the same drug is similar.This method is simple,efficient,environment-friendly and suitable for rapid screening and quantification of 26 kinds of CCs residues in eggs. |
PDF Full Text Request