固相萃取/超高效液相色谱-串联质谱法测定咖啡中21种真菌毒素

Determination of 21 Mycotoxins in Coffee by Solid Phase Extraction Coupled with UPLC-MS/MS

建立了咖啡中21种真菌毒素的固相萃取/超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。咖啡样品经乙腈-水-甲酸(80∶19∶1,体积比)溶液提取,使用0.05 g氧化镁结合Captiva EMR-Lipid柱净化提取液。以甲醇和1 mmol/L甲酸铵-0.1%甲酸水溶液为流动相,采用Agilent ZORBAX Eclipse Plus C18(2.1 mm×100 mm,1.8μm)色谱柱分离,在电喷雾离子源正、负离子切换多反应监测模式下测定,基质匹配标准曲线外标法结合同位素内标法(伏马毒素)进行定量分析。结果表明,咖啡中21种真菌毒素在各自的质量浓度范围内线性关系良好,相关系数(r2)大于0.998,检出限和定量下限分别为0.001~2.000μg/kg和0.003~6.000μg/kg,在低、中、高3个加标水平下的平均回收率为78.2%~106%,相对标准偏差为0.93%~9.5%。将该方法用于13份市售咖啡制品的检测,其中5份样品中检出新兴真菌毒素恩镰孢菌素、白僵菌素,最高检出值为17.1μg/kg。该方法简单快速、灵敏度高、准确性好,可应用于咖啡中21种真菌毒素的同时测定。

A method for the determination of 21 mycotoxins in coffee by ultra-high performance liq⁃uid chromatography-tandem mass spectrometry(UPLC-MS/MS)was developed.Coffee samples were extracted with acetonitrile-water-formic acid solution(80∶19∶1,volume ratio),cleaned up by 0.05 g magnesium oxide and Captiva EMR-Lipid solid phase extraction column.Methanol and 1 mmol/L ammonium formate solution(containing 0.1%formic acid)were used as mobile phases with gradient elution.The sample solution was separated by Agilent ZORBAX Eclipse Plus C18 column(2.1 mm×100 mm,1.8μm).The detection was performed under multiple reaction monitoring(MRM)of electrospray ionization in positive and negative ion modes.The matrix matching curve ex⁃ternal and internal standard(fumonisin)method were used for quantification.The results showed that 21 mycotoxins had good linear relationships within their respective mass concentration ranges(r2>0.998).The limits of detection(LODs)were 0.001-2.000μg/kg,and the limits of quantification(LOQs)were 0.003-6.000μg/kg.Average recoveries at three spiked levels were 78.2%-106%with relative standard deviations(RSDs)of 0.93%-9.5%.A total of 13 samples of coffee product were de⁃tected using the established method and the results showed that beauvercin and enniatins were detect⁃ed and the maximum content was 17.1μg/kg.The method is quick,easy,accurate and sensitive,which is suitable for the simultaneous determination of 21 mycotoxins in coffee product.