婴幼儿配方粉中香兰素和乙基香兰素的检测方法比较

目的 建立婴幼儿配方粉中香兰素、乙基香兰素的液相色谱法和同位素稀释液相色谱质谱联用两种测定方法。方法 液相色谱法: 样品经乙酸锌沉淀蛋白、Oasis MAX SPE柱净化, HSS T3色谱柱分离后, 在279 nm波长处进行检测, 外标法定量。同位素稀释液质联用法: 样品采用乙腈沉淀蛋白稀释净化后, 采用Waters BEH C18柱分离, 在质谱检测器多反应监测(UPLC-MS/MS)模式下, 用同位素稀释液质联用法进行检测。结果 液相色谱法: 香兰素、乙基香兰素的定量下限(LOQ)均为0.1 mg/kg。香兰素的方法回收率为88%~90.8 %, 相对标准偏差(RSD)小于5.2 %; 乙基香兰素的方法回收率为84%~93.3 %, RSD小于6.2 %。同位素稀释液质联用法香兰素、乙基香兰素的LOQ分别为香兰素1、0.5 mg/kg。香兰素、乙基香兰素的方法回收率分别为82.1%~91.2 %、90.2%~97.6 %, RSD分别小于6.1 %、5.8 %。结论 本文建立的两种方法对同一样品的检测结果一致, 为婴幼儿配方粉中香兰素、乙基香兰素的定量检测提供了较为理想的方法。

Comparison of quantification methods of vanillin and ethyl vanillin in infant formulas

Objective To establish quantitative methods of vanillin and ethyl vanillin in infant formulas by a ultra pressure liquid chromatography-ultraviolet spectrometer (UPLC-UV) and a ultra pressure liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). Methods In the UPLC-UV method, samples were purified and concentrated by Oasis MAX solid-phase extraction (SPE) cartridges after protein precipitation with zinc acetate. The vanzillin and ethyl vanillin elution were separated by an HSS T3 column, and detected by the UV detector at a wavelength of 279 nm. In the UPLC-MS/MS method, the protein was precipitated by acetonitrile. The supernatant were separated by a Waters BEH C18 column and quantified by isotope dilution liquid chromatography combined with mass spectrometry under multiple reaction monitoring (MRM) mode. Results LOQ of vanillin and ethyl vanillin were 0.1 mg/kg, as well as the overall spiked recoveries were 88%~90.8% (RSD<5.3%) for vanillin and 90.2%~97.6% (RSD<6.5%) for ethyl vanillin in UPLC-UV method. In UPLC-MS/MS method, LOQ of vanillin and ethyl vanillin were 1 mg/kg and 0.5 mg/kg, and the overall spiked recoveries were 82.1%~91.2% (RSD<6.1% ) for vanillin and 90.2%~97.6% (RSD<5.8%) for ethyl vanillin. Conclusion As the similar performances including good repeatability and high sensitivity, UPLC-UV and UPLC-MS/MS can be used as a routine method for the determination of e vanillin and ethyl vanillin in infant formulas.