超高效液相色谱-串联质谱法测定燕麦粉和小米粉中白僵菌素和恩镰孢菌素

Determination of beauvericin and enniatins in oat flours and millet flours by ultra performance liquid chromatography-tandem mass spectrometry

目的建立一种超高效液相色谱-串联质谱法测定谷物性食品燕麦粉和小米粉中白僵菌素(beauvercin,BEA)、恩镰孢菌素A、恩镰孢菌素A_(1)、恩镰孢菌素B和恩镰孢菌素B_(1)残留的分析方法。方法样品采用乙腈-水-甲酸(84:15:1,V:V:V)提取、经过Oasis Prime HLB固相萃取柱净化后,WatersBEH C_(18)色谱柱(100 mm×2.1 mm,1.8μm)分离,在正离子模式下,以5 mmol/L乙酸铵水溶液-乙腈为流动相进行梯度洗脱,在多反应监测模式下进行定性定量检测分析,基质匹配标准曲线外标法定量。结果BEA和4种恩镰孢菌素在各自的线性范围内具有良好的线性关系(r^(2)>0.999),方法检出限为0.02~0.05μg/kg,定量限为0.05~0.15μg/kg。按线性范围的最低浓度、中浓度和最高浓度3个水平进行加标回收实验,燕麦粉和小米粉的平均回收率分别是83.6%~105.2%和88.5%~104.2%,相对标准偏差分别为1.3%~8.2%和1.3%~3.2%(n=6)。对北京市采集的10份燕麦粉和10份小米粉样品进行检测,5种化合物均有不同程度检出,其中,恩镰孢菌素B和恩镰孢菌素B_(1)的检出率为100%。结论本方法简单快速、准确性好、灵敏度高,可以实现对燕麦粉和小米粉中白僵菌素和恩镰孢菌素进行准确的定性定量。

Objective To establish an ultra performance liquid chromatography-tandem mass spectrometry method for the determination of beauvercin(BEA),enniatin A,enniatin Ar,enniatin B and enniatin B in cereal food oat flour and millet flour.Methods The sample was extracted by acetonitrile-water-formic acid(84:15:1,V:V:V),purified by Oasis Prime HLB solid phase extraction column,and separated by Waters BEH C_(18) column(100 mm×2.1 mm,1.8μm).In positive ion mode,gradient elution was carried out with 5 mmol/L ammonium acetate aqueous solution-acetonitrile as mobile phase,qualitative and quantitative detection and analysis were carried out in multiple reaction monitoring mode,and the matrix matching standard curve external standard method was used for quantitative analysis.Results The results showed good linearity(r^(2)>0.999)in the respective linear ranges of BEA and 4 kinds of enniatins,with the limits of detection of 0.02-0.05μg/kg and the limits of quantification of 0.05-0.15μg/kg.The accuracy of the method was evaluated by conducting a recovery test at 3 spiked levels:The lowest,middle and highest concentrations of the linear ranges.The average recoveries for oat flours and millet flours were 83.6%-105.2%and 88.5%-104.2%,respectively,with the relative standard deviations of 1.3%-8.2%and 1.3%-3.2%(n=6).The 5 kinds of compounds were detected in different degrees in 10 samples of oat flour and 10 samples of millet flour collected in Beijing,among which,the detection rates of enniatin B and enniatin B were 100%.Conclusion The method is quick,easy,accurate and sensitive,which is suitable for the accurate qualitative and quantitative determination of beauvericin and enniatins in oat flour and wheat flour.