液质联用法同时检测动物源性食品中氯霉素和甲硝唑

目的 建立同时检测动物源性食品中氯霉素和甲硝唑的液相色谱-串联质谱法。方法 在试样中加入d5-氯霉素和d4-甲硝唑,经提取净化、浓缩、过滤后用液相色谱-串联质谱(LC-MS/MS)同时进行检测。结果 该方法线性范围均为0.25~5.0ng/ml,氯霉素和甲硝唑的检出限均为0.1μg/kg(S/N=3),定量限均为0.3μg/kg(S/N=10),线性范围均为0.25~5.0ng/ml,方法相对标准偏差(RSD)小于8%,样品加标回收率在85%~101%之间。240份畜肉样品中未检出氯霉素和甲硝唑;禽肉样品中氯霉素检出率为3.3%(2/60),甲硝唑检出率为1.7%(1/60)。水产品中氯霉素检出率为34.3%(24/70),未检测出甲硝唑,其中贝类样品中氯霉素检出率为43.3%(13/30)。结论 该方法快速、灵敏、准确,可用于动物源性食品中氯霉素和甲硝唑同时测定。

Determination of chloramphenicol and metronidazole in animal-origin foods by LC-MS/MS

Objective To establish a method for the determination of chloramphenicol and metronidazole by liquid chromatography-tandem mass spectrometry(LC-MS/MS).Methods After d5-chloramphenicol and d4-metronidazole were spiked into the samples,the target chemicals were extracted,purified,concentrated and filtered.Then,the target chemicals were determined by LC-MS/MS.Results The linear range of this method was at 0.25~5.0 ng/mL.The detection limits were both 0.1 μg/kg(LOD,S/N=3),and the limits of quantification were both 0.3μg/kg(LOQ,S/N=10).The relative standard deviation(RSD)was less than 8% and the sample added recovery was from 85% to 101%.Chloramphenicol and metronidazole were not detected in 240 meat samples.The detection rate of chloramphenicol in poultry meat samples was 3.3%(2/60),and that of metronidazole was 1.7%(1/60).The detected rate of chloramphenicol in aquatic products was 34.3%(24/70),while metronidazole was not detected.The detection rate of chloramphenicol in shellfish samples was 43.3%(13/30).Conclusion The proposed method is rapid,sensitive and accurate,which enable the reliable analysis of chloramphenicol and metronidazole in animal-origin foods.