基于果核壳的元素和稳定同位素比值测定及车厘子产地分析

Determination of Elements and Stable Isotope Ratios in Cherry Kernel Shells and Analysis of the Geographical Origin of Cherries

摘要:

该研究应用电感耦合等离子体质谱仪（ICP-MS），元素分析-稳定同位素比质谱仪（EA-IRMS）对车厘子果核壳中37种元素含量和氢、氧、碳、氮稳定同位素比值进行测定，并应用于车厘子产地分析中。车厘子去果肉和果仁后，将果核壳烘干并研磨成粉末，微波消解后通过ICP-MS对元素含量进行测定，果核壳粉末通过元素分析-稳定同位素比质谱仪对氢、氧、碳、氮稳定同位素比值（δ2H、δ18O、δ13C和δ15N）进行测定。应用上述方法对澳大利亚、美国、新西兰、智利和中国的车厘子样品进行元素含量和稳定同位素比值的测定，并对检测结果进行方差分析、主成分分析、聚类分析和判别分析，对车厘子产地的归属进行研究。研究结果表明基于车厘子果核壳的元素含量和稳定同位素比值综合分析，可以对车厘子产地进行区分，其中Mn、Co、Rb、Sr、Ba和δ2H组合指标整体交叉检验判别准确率92.1%。

Abstract:

Inductively coupled plasma-mass spectrometry (ICP-MS) and elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) were used to determine the contents of 37 elements and stable isotope ratios of hydrogen, oxygen, carbon, and nitrogen (δ2H, δ18O, δ13C, and δ15N, respectively) in the kernel shells of cherries and applied to identify their geographical origin. After removing the pulp and kernels of cherries, the kernel shells were dried and ground to a powder. After microwave digestion, the element contents of the kernel shell powder were determined using ICP-MS. Moreover, δ2H, δ18O, δ13C, and δ15N of the kernel shell powder were determined using EA-IRMS. The elemental contents and stable isotope ratios of cherry samples from Australia, the United States of America, New Zealand, Chile, and China were evaluated. Multivariate analyses of elements, including analysis of variance, Duncan’s multiple comparison, correlation analysis, principal component analysis, cluster analysis, and discriminant analysis, were performed using the relevant SPSS packages to attribute the geographical origin of the cherries. Combined indicators of Mn, Co, Rb, Sr, Ba, and δ2H were the most effective in tracing cherries to their geographical origin, with an overall cross-validation accuracy of 92.1%.