超高效合相色谱-质谱法快速检测工业油酸中5种常见的脂肪酸

Rapid Detection of Five Common Fatty Acids in Industrial Oleic Acid Based on Ultra Performance Convergence Chromatography-Mass Spectrometry

采用超高效合相色谱-质谱（UPC2-MS）技术,建立了工业油酸中5种常见的脂肪酸（软脂酸、硬脂酸、油酸、亚油酸和亚麻酸）的快速检测方法。样品用正己烷溶解,采用超临界CO2-甲醇/乙腈（1∶1,V/V）梯度洗脱,经Acquity UPC^2BEH 2-EP色谱柱（100 mm×2.1 mm,1.7μm）分离,通过质谱检测器在负离子电喷雾模式下对目标化合物进行分析,外标法定量。通过对UPC^2-MS条件的优化,5种脂肪酸在3 min内实现有效分离,目标物在0.5～100 mg/L范围内具有良好的线性（相关系数大于0.9985）;在3个添加水平下,5种脂肪酸的回收率在89.3%～106.7%之间,相对标准偏差为0.8%～3.0%;方法检出限（S/N≥3）为0.07～0.26 mg/L。实际样品分析结果表明,本方法不但简单快速,分离效果好,而且无需对脂肪酸样品进行衍生化,同时为UPC2在油脂类相关领域的研究与开发提供一种快速有效的检测方法。

A rapid method was developed for the determination of 5 common fatty acids,palmitic acid,stearic acid,oleic acid, linoleic acid and linolenic acid in industrial oleic acid based on ultra-performance convergence chromatography-mass spectrometry（ UPC-MS）. The sample was dissolved by n-hexane,followed by clean-up of extract using 0. 22 μm organic phase filter. The fatty acids were separated in 3 min on the column of Acquity UPC^2 BEH 2-EP by gradient elution with carbon dioxide and methanol / acetonitrile（ 1∶ 1,V / V） system,and finally detected by MS detector in ESI-mode. Through the optimization of UPC^2-MS condition,the reasonable linearity was achieved for all the analytes over the range of 0. 5- 100 mg / L with the correlation coefficients（ R^2） greater than 0. 9985. The recoveries for five fatty acids at three spiked levels were in the range from 89. 3% to 106. 67% with relative standard deviations of 0. 8%- 3. 0%. The limits of detection for target compounds in the method ranged from 0. 07 mg / L to 0. 26 mg / L. The real sample analysis showed that this method was simple,fast and had a good separation effect. There was no need of derivatization for fatty acid samples. This work would provide a fast and effective detection method for UPC2 technology in oil related research field.