基于UPLC-Triple-TOF-MS液质联用技术分析薏苡仁中的脂肪酸及其酯类化学成分

Analysis of chemical constituents of fatty acids and their esters of Coicis Semen by UPLC-Triple-TOF-MS

目的通过超高液相色谱串联三重四级杆飞行时间质谱法(UPLC-Triple-TOF-MS)建立一种对薏苡仁中的脂肪酸及其酯类化学成分进行快速定性分析的方法。方法采用Agilent ZORBAX-SB C18色谱柱(250 mm×4.6 mm,5.0μm),流动相为乙腈-异丙醇(1∶1),等度洗脱,体积流量为1.0 mL/min,检测波长为210 nm,柱温为30℃,进样量为10μL。采用电喷雾离子源正离子模式,扫描范围为m/z 100~1500,并采用全扫描模式对样品数据进行收集,根据高分辨质谱结合二级质谱所得的信息对薏苡仁中脂肪酸及其酯类化学成分进行快速的鉴定。结果检测出薏苡仁中29种脂肪酸及其酯类化学成分,并对化合物的裂解规律进行分析。通过分子离子峰和碎片离子的质荷比、Scifinder和Reaxy网络数据库以及文献得知,这些化合物在离子源的作用下通过失去油酸、亚油酸、棕榈酸、氧化油酸等结构,得到不同质荷比的碎片离子,从而推测出29种脂肪酸及其酯类化合物的名称及结构式。结论研究建立的薏苡仁脂肪酸及其酯类化学成分定性分析的方法准确、快速、灵敏,为提高薏苡仁的质量控制水平及后续阐明薏苡仁的药效物质基础提供了实验依据。

Objective To establish a rapid qualitative analysis method for fatty acids and esters in Coicis Semen by ultra-performance liquid chromatography triple quadrupole time-of-flight mass spectrometry(UPLC-Triple-TOF-MS).Methods Agilent ZORBAX-SB C18(250 mm×4.6 mm,5.0μm)column was used.The mobile phase was acetonitrile-isopropanol(1:1)elution,the flow rate was 1 mL/min,the detection wavelength was 210 nm,the column temperature was 30℃,and the injection quantity was 10μL.Electrospray ion source positive ion mode was adopted,and the scanning range was m/z 100—1500.The sample data were collected by full scanning mode,and the fatty acid chemical composition of Coicis Semen was quickly identified according to the information obtained by high-resolution mass spectrometry combined with secondary mass spectrometry.Results A total of 29 kinds of fatty acids and esters in Coicis Semen were detected,and the cracking rules of the compounds were analyzed.Through the mass-to-charge ratio of molecular ion peaks and fragment ions,the Scifinder and Reaxy network databases,and the literature,these compounds were different under the action of ion source by losing the structure of oleic acid,linoleic acid,palmitic acid,oxidizing oleic acid and the like.The mass-to-charge ratio of the fragment ions,and the name and structural formula of the 29 fatty acids and their ester compounds were inferred.Conclusion The method of qualitative analysis of the fatty acids and esters of Coicis Semen established in this study is accurate,rapid and sensitive,which provides experimental basis for improving the quality control level of Coicis Semen and further elucidating the pharmacodynamic substance basis of Coicis Semen.