Steroid estrogens, such as estrone (E1), 17β-estradiol (E2) and estriol (E3), have been shown to exhibit potentially adverse effects on the health of children. Consequently, it is highly desirable to develop detection approaches for rapid and accurate determination of steroid estrogens in infant formulas. In this study, a robust method based on isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS) was developed to simultaneously measure E1, E2 and E3 in infant formulas with no need for any derivatization step. The desired simplicity, accuracy and specificity were achieved via a facile sample pretreatment process, including protein precipitation and clean-up steps. The limits of quantification were 0.0025, 0.005 and 0.005 μg kg⁻¹ for E1, E2 and E3, respectively. Besides, a recovery of 92.3–102.7% was obtained with a relative standard deviation of less than 6%. Furthermore, both accurate values for the target analytes ranging from 0.005 to 50 μg kg⁻¹ and a corresponding expanded relative uncertainty of less than 12% were obtained using the ID LC-MS/MS method. More importantly, the approach is highly sensitive, selective and accurate in screening estrogens in real infant formula samples. Thus, it could be convenient for large-scale application due to its derivatization-free feature and simplicity in sample preparation.

中文翻译：

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同位素稀释液相色谱-串联质谱法定量婴儿配方食品中的雌激素†

甾体雌激素，例如雌酮（E1），17β-雌二醇（E2）和雌三醇（E3），已显示出对儿童健康的潜在不利影响。因此，迫切需要开发一种检测方法，以快速，准确地测定婴儿配方食品中的类固醇雌激素。在这项研究中，开发了一种基于同位素稀释液相色谱-串联质谱（ID LC-MS / MS）的可靠方法，无需任何衍生步骤即可同时测量婴儿配方食品中的E1，E2和E3。通过简便的样品预处理过程（包括蛋白质沉淀和纯化步骤）可以实现所需的简单性，准确性和特异性。定量限为0.0025、0.005和0.005μgkg ^-1分别针对E1，E2和E3。此外，回收率达到92.3–102.7％，相对标准偏差小于6％。此外，使用ID LC-MS / MS方法获得的目标分析物的准确值范围在0.005至50μgkg ^-1之间，并且相应的扩展相对不确定度小于12％。更重要的是，该方法在筛选真实婴儿配方食品样品中的雌激素时具有很高的敏感性，选择性和准确性。因此，由于其无衍生特性和样品制备简单性，对于大规模应用而言可能很方便。