冬青油真伪鉴别方法研究

Research on Identification of Wintergreen Oil

通过比较傅里叶变换红外光谱技术(FTIR)、气相色谱-质谱联用技术(GC-MS)、核磁共振波谱技术(NMR)、气相色谱-燃烧-稳定同位素比值质谱技术(GC-C-IRMS),建立了有效鉴别天然冬青油的方法。FTIR结果表明,样品均含有天然冬青油的官能团;GC-MS结果表明其主成分均为水杨酸甲酯;而NMR定性结果显示样品均为水杨酸甲酯的C、H结构,并利用核磁共振对样品进行了绝对定量;碳、氢稳定同位素测定结果显示天然冬青油、冬青油的δD、δ13C值偏负,合成水杨酸甲酯、疑似合成冬青油的δD、δ13C值偏正。结果表明,稳定同位素比值质谱技术可以有效鉴别天然冬青油。

The approach to identification of wintergreen oil is established by comparing FTIR,GC-MS,NMR,and GC-C-IRMS.The results of FTIR indicate that the functional groups of wintergreen oil are found in all samples.Methyl salicylate is the principal component of the samples,which is indicated by the results of GC-MS.C and H structures of methyl salicylate are discovered by analyzing the qualitative results of NMR,and quantitative analysis by NMR is carried out.The results of C and H measurement by GC-C-IRMS show that the values of[WTBX]δD and[WTBX]δ13 C of natural wintergreen oil and wintergreen oil are negative,and the values of[WTBX]δD and[WTBX]δ13 C of synthetic methyl salicylate and suspected synthetic wintergreen oil are positive.So GC-C-IRMS can be used to effectively identify natural wintergreen oil.