QuEChERS-高效液相色谱-串联质谱测定牛奶中6种玉米赤霉烯酮类毒素

Determination of Six Zeranols in Milk by QuEChERS-High Performance Liquid Chromatography-Tandem Mass Spectrometry

建立QuEChERS-高效液相色谱-串联质谱同时检测牛奶中6种玉米赤霉烯酮类毒素残留量的检测方法。样品用1%乙酸-乙腈提取,乙腈饱和正己烷除脂,C18、N-丙基乙二胺和无水硫酸镁净化,在ZORBAX SB-C18色谱柱上分离,以5 mmol/L NH4Ac溶液和乙腈作为流动相进行梯度洗脱,电喷雾离子源负离子模式扫描,多反应监测测定,基质匹配外标法定量分析。牛奶中6种玉米赤霉烯酮类毒素在0.1～50μg/L质量浓度范围内呈线性关系,相关系数均高于0.995;检出限为0.05～0.1μg/kg,定量限为0.25～0.5μg/kg。牛奶中6种玉米赤霉烯酮类毒素的3个加标水平的平均回收率范围为91.8%～114.5%,相对标准偏差在3.2%～14.4%之间(n=6)。

A method for simultaneous determination of six zeranols residues in milk was developed by quick, easy cheap,effective, rugged and safe(QuEChERS) extraction coupled to high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS). The sample was extracted with 1% acetate acetonitrile. The extract was degreased with acetonitrile-saturated n-hexane, cleaned up with a mixture of C18, primary secondary amine(PSA) and magnesium sulfate anhydrous. The analytes were separated on a reversed phase C18 column and gradiently eluted with 5 mmol/L ammonium acetate and acetonitrile. These analytes were analyzed under the multiple reaction monitoring(MRM) mode with negative electrospray ionization(ESI-) and quantified by matrix-matched external standard method. Good linearity was obtained for the six zeranols in the concentration range of 0.1–50 μg/L with correlation coefflcients of more than 0.995. The limits of detection(LODs) and the limits of quantiflcation(LOQs) for the zeranols were 0.05–0.1 and 0.25–0.5 μg/kg, respectively.The recoveries at three spiked concentration levels were in the range of 91.8%–114.5%. The repeatability expressed as relative standard deviation(RSD) ranged from 3.2% to 14.4%(n = 6).