色谱 ›› 2021, Vol. 39 ›› Issue (4): 406-414.DOI: 10.3724/SP.J.1123.2020.05012

• 研究论文 • 上一篇    下一篇

固相萃取-超高效液相色谱-串联质谱法同时测定动物源性食品中11种禁限兽药及代谢物

刘柏林*(), 谢继安, 赵紫微, 王秀莉, 单晓梅   

  1. 安徽省疾病预防控制中心, 安徽 合肥, 230601
  • 收稿日期:2020-05-29 出版日期:2021-04-08 发布日期:2021-03-08
  • 通讯作者: 刘柏林
  • 作者简介:*E-mail: liubolin087@163.com.

Simultaneous determination of 11 prohibited and restricted veterinary drugs and their metabolites in animal-derived foods by ultra performance liquid chromatography-tandem mass spectrometry coupled with solid phase extraction

LIU Bolin*(), XIE Jian, ZHAO Ziwei, WANG Xiuli, SHAN Xiaomei   

  1. Anhui Provincial Center for Disease Control and Prevention, Hefei 230601, China
  • Received:2020-05-29 Online:2021-04-08 Published:2021-03-08
  • Contact: LIU Bolin

摘要:

建立了固相萃取-超高效液相色谱-串联质谱(SPE-UPLC-MS/MS)同时检测鸡蛋、液态奶、鸡肉及淡水鱼中4类(氯霉素类、硝基咪唑类、林可酰胺类与大环内酯类)8种禁限兽药与3种代谢物残留的分析方法。对样品前处理及色谱条件进行优化,样品经0.1 mol/L pH 9.0的磷酸盐缓冲液水解分散,乙腈提取,提取液经乙酸乙酯萃取后浓缩至近干,残留物用0.3 mL甲醇溶解,再加入5.7 mL磷酸盐缓冲液,混匀,溶解液经Oasis HLB固相萃取柱净化后上机分析,以甲醇与0.1%甲酸水溶液作为流动相进行梯度洗脱,经ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm, 1.7 μm)分离,采用ESI+和ESI-电离,在多反应监测模式下采集,同位素内标法定量。结果表明,11种待测物在色谱柱上完全基线分离,在各自范围内线性关系良好,相关系数(R2)>0.99,方法的检出限(LOD)为0.050~0.50 μg/kg,定量限(LOQ)为0.20~1.5 μg/kg。各待测物的平均回收率为65.3%~108%,相对标准偏差(RSD)为0.40%~21%。将该方法应用于市售样品中上述4类兽药残留的常规监测,其阳性样本的检测结果与标准方法测定结果无显著性差异。该方法灵敏度高,稳定性好,定量准确,适用于动物源性食品中多种禁限兽药及代谢物残留的同时快速测定。

关键词: 超高效液相色谱-串联质谱, 固相萃取, 基质效应, 同位素内标, 兽药残留, 代谢物, 动物源性食品

Abstract:

Chloramphenicols, nitroimidazoles, lincosamides, and macrolides are common antibiotics used in veterinary medicine. Overdoses of these drugs will lead to residual substances in animal-derived foods and accumulate in the body through the food chain, thereby exerting adverse effects on human health. Therefore, regulation of veterinary drug levels is imperative to ensure the quality of animal-derived foods and safeguard the health of consumers. In this study, a method based on ultra performance liquid chromatography-tandem mass spectrometry coupled with solid phase extraction (SPE-UPLC-MS/MS) was developed for the simultaneous determination of eight prohibited and restricted veterinary drugs and three metabolite residues across four categories (chloramphenicols, nitroimidazoles, lincosamides, and macrolides) in eggs, liquid milk, chicken, and freshwater fish. The main factors affecting the response, recovery, and sensitivity of the method, such as the type and pH values of the extraction solvent, dilution solution for the analytes, type of chromatographic column, and type and proportion of the mobile phase, were optimized during sample pretreatment and instrument analysis. The samples were hydrolyzed and dispersed in 0.1 mol/L phosphate buffer solutions (pH 9.0) and extracted with acetonitrile. The extract was further extracted using ethyl acetate. After centrifugation, the supernatant ethyl acetate was concentrated to near dryness in nitrogen below 40 ℃. The residue was dissolved in 0.3 mL methanol, followed by the addition of 5.7 mL phosphate buffer solution. After shaking, the solutions were purified and enriched on an Oasis HLB SPE column. The target analytes were separated on an ACQUITY UPLC BEH C18 chromatographic column (100 mm×2.1 mm, 1.7 μm) at a column temperature of 40 ℃ with a flow rate of 0.4 mL/min. The injection volume was 10 μL. Gradient elution was carried out with methanol and 0.1% formic acid aqueous solution as the mobile phases. Multiple reaction monitoring (MRM) was conducted in the positive and negative electrospray ionization modes. The isotope internal standard method was used for quantitative analysis. Under optimal conditions, each analyte showed a good linear relationship in each range, and the correlation coefficient (R2) was greater than 0.99. The limits of detection (LODs) ranged from 0.050 to 0.50 μg/kg, and the limits of quantification (LOQs) ranged from 0.20 to 1.5 μg/kg. With eggs, freshwater fish, chicken, and liquid milk as the matrix samples, the recoveries in spiked blank samples were determined at different addition levels in compliance with the current legislation. The average recoveries of the 11 analytes were 65.3% to 108%. The relative standard deviations (RSDs) were between 0.40% and 21%. The matrix effects of the analytes were between 0.0124% and 46.80% in four different samples after purification on the Oasis HLB column. The practicality of the proposed approach for routine analyses of the eight prohibited and restricted veterinary drugs, and three metabolite residuals was evaluated by applying it to the determination of these compounds in animal-derived food samples. The samples, including 80 eggs, 80 chicken, 40 liquid milk, and 32 freshwater fish, were procured from a supermarket and a farm product market. The results of the positive samples were consistent with those observed with the standard methods. The method described herein is easy to operate, sensitive, and accurate. It is suitable for the simultaneous and rapid determination of various prohibited and restricted veterinary drug residues and metabolites in animal-derived foods.

Key words: ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS), solid phase extraction (SPE), matrix effect (ME), isotope internal standard, veterinary drug residues, metabolites, animal-derived foods

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