利用电喷雾质谱仪快速鉴定二咖啡酰喹宁酸的取代位置

目的确定二咖啡酰喹宁酸的取代位置。方法利用电喷雾质谱仪ESI-MS（n）的四极杆离子阱多级质谱技术，根据质谱裂解规律，归属咖啡酰喹宁酸衍生物主要的离子峰。结果不同取代的二咖啡酰喹宁酸在电喷雾质谱四极杆离子阱中具有一定的特点和规律。结论在三级负离子质谱中，脱掉两个咖啡酰基的碎片离子强度很大，为基峰时，可以判断衍生物没有4位取代。3，5-取代和4，5-取代可以通过比较P值（一级质谱中的基峰峰高与二级质谱中的基峰峰高之比）来判断，当3，4位有取代基时其P值大于4，5位有取代基时的P值。

Fast determination of substitutional positions of dicaffeoylquinic acid by ESI-MS(n)

Aim To identify the substitutional positions of dicaffeoylquinic acid.Methods Utilizing ESI-ion trap MS technology and according to the fragments of mass spectrum,the main mass spectrum peaks of the ions has been identified.Results Different substitutes of dicaffeoylquinic acid exhibit distinct ion peaks.Conclusions If the ion peak which is formed by taking off two caffeoyl groups is the basic peak in-MS(3),it shows that there may be no 4-substitute.3,5-Substitution and 4,5-substitution can be distinguished by comparing P value the height of the ion in-MS/the height of the ion in-MS(2)].The P value of 3,4-dicaffeoylquinic acid is bigger than that of 4,5-dicaffeoylquinic acid.The 1H-NMR characters of this kind of compounds and the correct serial number of quinic acid were also introduced.