摘要
建立了牛奶中甲巯咪唑、硫脲嘧啶、甲基硫氧嘧啶、丙基硫氧嘧啶、苯基硫氧嘧啶和2-巯基苯并咪唑6种甲状腺拮抗剂残留的液相色谱-串联质谱分析方法。样品经乙腈沉淀蛋白后,上清液以衍生剂4-碘苄溴在pH=8.0下衍生2 h,衍生液调节至pH=3.0,以乙酸乙酯提取。溶剂挥干后以20%甲醇复溶,Oasis HLB固相萃取小柱净化,4 mL 50%甲醇-乙腈溶液洗脱,Luna C18色谱柱分离,乙腈和5 mmol/L乙酸铵溶液(含0.2%甲酸)进行梯度洗脱,电喷雾正离子模式电离(ESI+),多反应监测(MRM)模式检测,内标法定量。结果表明:牛奶中6种目标物在优化条件下分离良好,响应值高,峰形尖锐对称,在5～100!g/kg范围内呈良好的线性关系,相关系数r2均大于0.99;检出限为0.14～0.32!g/kg,定量限为0.48～1.1!g/kg;10,20和50!g/kg添加水平的平均回收率为82.8%～113.6%,相对标准偏差2.4%～14.3%。
A liquid chromatography-tandem mass spectrometric method was established for the determination of six thyroid antagonists residues in milk including tapazole, 2-thiouracil, 6-methyl-2-thiouracil, 6-propyl-2- thiouracil, 6-phenzyl-2-thiouracil and 2-mercaptobenzimidazole. The supernate of sample was derived with 4- iodobenzyl bromide （4-IBBr） at pH 8.0 for 2 h after protein precipitation by acetonitrile. The solution was then checked to pH = 3.0 with HC1 solution and extracted with ethyl acetate. After solvent evaporation, resi- due was dissolved with 20% methanol aqueous. Purification was carried out on an Oasis HLB cartridge, 4 mL 50% methanol-acetonitrile solution was used to elute. Separations of six antagonists and internal standard were performed on a Luna Cls column with mobile phase containing acetonitrile and 0.2% （V/V） formic acid- 5 mmol/L ammonium acetate aqueous solution in a gradient elution mode. The identification and quantification of drugs were carried out by positive electrospray ionization （ESI＋） in multiple reaction monitoring （MRM） mode, the quantification analyses were performed by internal standard method. Results indicated that chromatographic peaks of 6 thyroid antagonists were sharp, symmetry, and had been separated well with each other. The calibration curves showed good linearity in the range of 5- 100 gg/kg with correlation coefficients R2〉0. 99 in milk. Limits of detections （LODs） of six thyroid antagonist were 0.14-0.32 gg/kg, limits of quantities （LOQs） were 0.48- 1. 1μg/kg, respectively. The average recoveries spiked at 10, 20 and 50 gg/kg levels in milk were 82.8% -113.6% , and the relative standard deviations （RSDs） were 2.4% - 14.3%.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2013年第2期253-257,共5页
Chinese Journal of Analytical Chemistry
基金
国家质检总局科技计划(No.2012IK033)资助
