同位素稀释-气相色谱-质谱法同时测定婴儿配方乳粉中的4种香料

Simultaneous determination of 4 kinds of flavors in infant formulas by isotope dilution-gas chromatography-mass spectrometry

中文关键词:  香兰素  甲基香兰素  乙基香兰素  香豆素  气相色谱-质谱法  同位素稀释  婴儿配方奶粉

英文关键词:vanillin  methyl vanillin  ethyl vanillin  coumarin  gas chromatography-mass spectrometry  isotope dilution  infant formulas

中文摘要:

      目的 建立用同位素稀释-气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)同时测定婴幼儿配方乳粉中香兰素、甲基香兰素、乙基香兰素和香豆素4种香料的方法。方法 样品经饱和氯化钠水溶液溶解后加入同位素内标, 经乙腈超声提取后离心取上清液, 加入正己烷去除脂类。萃取液浓缩定容后, 采用VF-WAXms色谱柱(30 m×0.25 mm, 0.25 μm)分离目标物, 利用质谱在全扫描模式和选择离子扫描模式同步扫描模式下, 对4种香料及其同位素内标物进行检测, 用内标法定量。结果 该方法在16 min 内即可完成4种化合物的分离分析。4种化合物在0.05~5.0 mg/L范围内线性关系良好, 相关系数均高于0.999, 定量限为0.03 mg/kg, 在3个加标水平(0.1、1.0、5.0 mg/kg)下, 4种化合物的平均回收率为85.7%~98.3%, 相对标准偏差(relative standard deviation, RSD)不大于5.0%。结论 该方法快速、准确、灵敏, 适合婴幼儿配方粉中香兰素、甲基香兰素、乙基香兰素和香豆素4 种香料的同时测定。

英文摘要:

      Objective To establish a method for simultaneous determination of 4 kinds of flavors (vanillin, methyl vanillin, ethyl vanillin and coumarin) in infant formulas by isotope dilution-gas chromatography-mass spectrometry (GC-MS). Methods Samples were dissolved in a saturated sodium chloride solution and then adding the isotope internal standards. After ultrasonic extraction with acetonitrile, hexane was added to the centrifugal supernatant to remove lipids. Then the extracts were concentrated by nitrogen and were separated by VF-WAXms capillary column (30 m×0.25 mm, 0.25 μm). Four kinds of flavors and their isotope internal standards were detected by mass spectrometry in full scan mode and selective ion scan mode synchronous scanning mode and quantified by internal standard solution. Results This method could complete the separation and analysis of 4 compounds in 16 min. Four kinds of flavors had a good linear relationship within the concentration range of 0.05-5.0 mg/L and the correlation coefficients were all more than 0.999. The limits of quantitation of 4 compounds were 0.03 mg/kg. The recoveries at 3 spiked levels (0.1, 1.0, 5.0 mg/kg) were 85.7%-98.3% and all relative standard deviation (RSD) were lower than 5.0%. Conclusion This method is fast, accurate and sensitive, which is suitable for determination of vanillin, methyl vanillin, ethyl vanillin and coumarin in infant formulas.