乳及乳制品中稳定碳同位素比的研究

Detection of carbon isotope ratio of milk and dairy products

中文关键词:  稳定同位素比质谱法  碳同位素比  牛乳  羊乳  母乳

英文关键词:elemental analyzer-isotope ratio mass spectrometry  carbon isotope ratio  milk  goat milk  breast milk

中文摘要:

      目的 建立元素分析-稳定同位素比质谱法(elemental analyzer-isotope ratio mass spectrometry, EA-IRMS)测定乳及乳制品中δ13C值的检测方法。方法 本文研究了样品前处理、进样量、不同标样标定等对测定结果的影响, 通过优化仪器工作条件, 建立了稳定同位素比质谱仪测定乳及乳制品中碳同位素比(δ13C)的方法, 并用该方法对20余种品牌的乳及乳制品及3位哺乳期的母乳进行检测。结果 研究数据表明, 不同种类的乳汁δ13C数值有明显差异: 牛乳及其制品δ13C值位于-16.50‰~-20.42‰, 羊乳及其制品δ13C值位于-22.38‰~-22.95‰, 母乳δ13C值为-23.17‰~-27.30‰。结论 本方法根据羊乳和与牛乳δ13C特征数值的差异, 可以进行乳品纯正性判别。该方法精密度为0.04‰~0.24‰, 小于常规0.3‰的要求, 稳定性好、准确度高, 操作简便, 为乳及乳制品的鉴别提供了技术支持和理论基础。

英文摘要:

      Objective To establish a method for analyzing the δ13C in milk and dairy products by elemental analyzer-isotope ratio mass spectrometry (EA-IRMS). Methods The influences of sample preparation, sample quantity and calibration of different standard samples were investigated. A stable isotope ratio (δ13C) was established to determine the ratio of carbon isotope (δ13C) in milk and dairy products by optimizing instrument working conditions. More than 20 kinds of milk, dairy products and 3 human milk in lactation period were tested by this method. Results The results indicated that, the δ13C values had significant differences in different kinds of milk: liquid milk and its products were -16.50‰~-20.42‰, goat milk and its products were -22.38‰~-22.95‰, and breast milk were -23.17‰~-27.30‰. Conclusion According to the difference in characteristic values of δ13C in goat milk and milk, this method can distinguish the purity of milk and dairy products. The precisions of the method are 0.04‰~0.24‰, which are less than the regular requirement of 0.3‰. The established method has a good stability and reproducibility, and easy to operate, which can provide technical support and theoretical basis for identify milk and dairy products.