气相色谱-质谱联用法快速检测乳制品中维生素E含量

Rapid determination of vitamin E content in dairy products by gas chromatography-mass spectrometry

中文关键词:  乳制品  α-生育酚  α-醋酸生育酚  气相色谱-质谱联用法

英文关键词:dairy products  α-tocopherol  α-tocopheryl acetate  gas chromatography-mass spectrometry

中文摘要:

      目的 建立正己烷涡旋辅助提取-气相色谱-质谱联用法(gas chromatography-mass spectrometry, GC-MS)快速检测乳制品中α-生育酚和α-醋酸生育酚的分析方法。方法 样品经甲醇沉淀蛋白后, 采用正己烷涡旋提取, 提取液以HP-5MS色谱柱分离, GC-MS选择离子监测模式测定。结果 α-生育酚和α-醋酸生育酚在0.05~10 mg/L浓度范围内线性关系良好, 相关系数均大于0.999; α-生育酚和α-醋酸生育酚检出限(S/N=3)分别为0.51 mg/kg和0.25 mg/kg, 定量限(S/N=10)分别为1.70 mg/kg和0.83 mg/kg。质控样NIST SRM 1849a检测值与参考值偏差为-3.75%, 日内相对标准偏差(RSD, n=5)为1.38%~2.25%, 日间相对标准偏差为1.83%。结论 该方法快速、准确、灵敏, 适用于乳制品中维生素E含量的快速测定。

英文摘要:

      Objective To established a rapid determination method of alpha-tocopherol and alpha-tocopheryl acetate in dairy products using vortex-assisted extraction and gas chromatography-mass spectrometry (GC-MS). Methods Samples were extracted with n-hexane after proteins were precipitated by methanol. Then the isooctane layer was separated by HP-5MS capillary chromatographic column and detected by selected ion monitoring (SIM) mode of GC-MS. Results Under the optimized conditions, the calibration curves of target analytes were linear in the range of 0.05~10 mg/L with correlation coefficients higher than 0. 999. Limits of detection (LODs, S/N=3) of α-tocopherol and α-tocopheryl acetate were respectively 0.51 mg/kg and 0.25 mg/kg, and limits of quantification (LOQs, S/N=10) were respectively 1.70 mg/kg and 0.83 mg/kg. The method was validated by NIST SRM 1849a, with the deviation of result and certified value at -3.75%. Intra-day relative standard deviations (RSDs) were between 1.38% and 2.25%, and inter-day RSD was 1.83%. Conclusion The proposed method is rapid, accurate and sensitive, which is suitable for the detection of vitamin E content in dairy products.