固相萃取-超高效液相色谱-同位素稀释串联质谱法测定蜂蜜中的甲硝唑和氯霉素

Simultaneous Determination of Metronidazole and Chloramphenicol in Honey by Solid Phase Extraction and Ultra Performance Liquid Chromatography-Isotope Dilution Tandem Mass Spectrometry

建立了同时测定蜂蜜中甲硝唑和氯霉素残留量的固相萃取-超高效液相色谱-同位素稀释串联质谱方法。蜂蜜样品中的甲硝唑和氯霉素经乙酸乙酯提取后,采用InertSep RP-1固相萃取柱对目标物进行富集和净化。经超高效液相色谱分离后,在三重四极杆质谱的多反应监测模式(MRM)下,甲硝唑通过正离子模式(ESI+)采集,氯霉素通过负离子模式(ESI-)采集,采用同位素稀释的内标法定量。本方法在浓度1~100ng/mL范围内具有良好的线性关系,相关系数R2>0.999。在添加水平为0.5、2.5、25μg/kg时,回收率在71.4%~123.4%之间,相对标准偏差为5.0%~12.3%。本方法采用一种前处理方式,可以同时测定蜂蜜中的甲硝唑与氯霉素残留,缩短了分析时间,提高了检测效率。

A reliable method using ultra high performance liquid chromatography coupled to tandem mass spectrometry（UPLC-MS/MS）for the simultaneous identification and quantitation of metronidazole and chloramphenicol in honey was developed and validated.The two analytes were extracted by ethyl acetate.An InertSep RP-1solid-phase extraction cartridge was used for the clean-up step.After the chromatographic separation on an Endeavorsil C18 column,metronidazole was detected by a triple quadrupole instrument operating in positive mode,and chloramphenicol was analyzed in negative mode,respectively.The quantification was achieved by isotope dilution internal standard method.The method showed a good linear response in the range of1-100ng/mL,with correlation coefficients exceeding 0.999 for the two compounds.The average recoveries at three spiked levels ranged from 71.4% to 122.4% with the relative standard deviations below 12.3%.The method has been successfully evaluated through application to honey samples.