复合免疫亲和柱净化-液相色谱-串联质谱法同时测定动物源性食品中6种玉米赤霉醇类化合物和氯霉素残留量

建立了动物源性食品中6种玉米赤霉醇类化合物和氯霉素残留量的复合免疫亲和柱净化、液相色谱-串联质谱（LC-MS/MS）分析方法。样品（鱼肉、肝脏、牛奶、蜂蜜）经β-葡萄糖苷酸/硫酯酸复合酶酶解后用乙醚提取，提取液经氮气吹干，残渣用50%乙腈溶液复溶后过滤，滤液用PBS溶液稀释，经复合免疫亲和柱富集净化后供LC-MS/MS检测，采用多反应监测（MRM）模式进行定量和定性分析，外标法定量。结果表明，7种目标物的检出限（S/N=3）在0.04~0.10 μg/kg之间，线性相关系数（R²）≥0.9990，平均回收率为70.9%~95.6%，相对标准偏差为2.0%~11.8%。该方法灵敏度高、重现性好，适用于动物源性食品中痕量玉米赤霉醇类药物和氯霉素残留的测定。

Simultaneous determination of zeranols and chloramphenicol in foodstuffs of animal origin by combination immunoaffinity column clean-up and liquid chromatography-tandem mass spectrometry

A combination immunoaffinity column (IAC-CZ) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was successfully developed for the simultaneous determination of zeranols (ZER,α-zearalanol,β-zearalanol, zearalanone,α-zearalenol,β-zearalenol and zearalenone) and chloramphenicol (CAP) in foodstuffs of animal origin. The samples (fish, liver, milk and honey) were enzymatically digested by β-glucuronidase/sulfatase for about 16 h and then extracted with ether. The extracts were evaporated to dryness and then the residues were dissolved by 1.0 mL of 50% acetonitrile solution. After filtered and diluted with PBS buffer, the reconstituted solution were cleaned-up with a IAC-CZ and then analyzed by LC-MS/MS in multiple reaction monitoring (MRM) mode. The chromatographic separation was performed on a Shimadzu Shim-pack VP-ODS column with gradient elution by acetonitrile and 2 mmol/L ammonium acetate solution. The detection was carried out by electrospray negative ionization mass spectrometry in MRM mode. The proposed method was validated by the limit of detection (0.04-0.10 μg/kg), linearity (R²≥0.9990), average recoveries (70.9%-95.6%) and precisions (2.0%-11.8%). The developed method is reliable, sensitive and has good applicability. The combination immunoaffinity column was proved to be an effective pretreatment technique to decrease the matrix effect, and it met the requirements of residue analysis of co-occurring zeranols and chloramphenicol.