应用基质固相分散技术和液相色谱-串联质谱法(LC-MS/MS)测定了禽蛋中的苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ染料。制备样品后装柱,用氯仿-乙腈(体积比为90∶10)混合溶剂洗脱,洗脱液浓缩定容后经ZORBAXSB-C18柱分离,采用电喷雾正离子多反应监控(MRM)模式质谱检测,外标法定量。苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ的线性范围分别为0.5~100ng/g,5.0~100ng/g,1.0~100ng/g和2.0~100ng/g,线性方程的相关系数均大于0.99。样品的添加回收率在87.3%~113%之间,相对标准偏差均小于9.1%。4种苏丹红染料的检测低限分别为0.1,2.0,0.2,0.4μg/kg,可以满足国内外禽蛋中苏丹红的监控要求。
A new method was established for determining Sudan RedⅠ-Ⅳ dyes in eggs using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The target analytes in eggs such as hen eggs, duck eggs and preserved eggs, were extracted by solid-phase dispersion technique with a mixture of chloroform-acetonitrile (9∶1, v/v). The chromatographic separation was achieved on a ZORBAX SB-C18 column. The identification and quantification were performed using MS/MS with multiple-reaction monitoring (MRM) and electrospray ionization in positive mode. The linearity ranges of Sudan Red Ⅰ-Ⅳ dyes were 0.5-100 ng/g, 5.0-100 ng/g, 1.0-100 ng/g and 2.0-100 ng/g, respectively, and all linear correlation coefficients were higher than 0.99. The recoveries of Sudan Red dyes in eggs were between 87.3% and 113% with the relative standard deviations less than 9.1%. The detection limits of this method were 0.1 μg/kg for Sudan RedⅠ, 2.0 μg/kg for Sudan Red Ⅱ, 0.2 μg/kg for Sudan Red Ⅲ and 0.4 μg/kg for Sudan Red Ⅳ, which couldmeet the monitoring requirements of the Sudan Red dyes both abroad and home.