反相高效液相色谱法测定Rancimat测量池水中的短链脂肪酸

摘要

The contents of short-chain fatty acids including formic acid,acetic acid,propionic acid,butyric acid,valeric acid and caproic acid were determined by reversed-phase high-performance liquid chromatography,and it could lay the foundation for the exploration of the internal composition changes mechanism of conductivity in Rancimat measuring cell water.The results showed that the optimal detection conditions were obtained as follows:flow rate 1.0 mL/min,column temperature 40℃,UV detection wavelength 210 nm,injection volume 10 μL and linear gradient elution of mobile phase consisted of methanol and phosphate solution (pH 2.8,0.05 moL/L).Under these conditions,formic acid,acetic acid,propionic acid,butyric acid,valeric acid and caproic acid could be separated simultaneously and the retention time was 1.96,2.71,5.81,13.47,19.33 min and 27.72 min,respectively.The average precision of peak area and average recovery rate of the method were 2.31％ and 96.88％ respectively.The short-chain fatty acids in palm oil,soybean oil and linseed oil in oxidation stability experiments were mainly formic acid and acetic acid.The method was of great significance for in-depth analysis and optimization of Rancimat evaluation experiment.%采用反相高效液相色谱法测定Rancimat测量池水中甲酸、乙酸、丙酸、丁酸、戊酸、己酸等短链脂肪酸含量,为探明Rancimat测量池水电导率的内在组成变化机理奠定基础.结果表明:高效液相色谱在流速1.0 mL/min、柱温40℃、紫外检测波长210 nm、进样量10 μL、流动相为磷酸盐溶液(pH 2.8,0.05 mol/L)和甲醇组成的线性梯度洗脱条件下,能同时分离甲酸、乙酸、丙酸、丁酸、戊酸、己酸,其保留时间分别为1.96、2.71、5.81、13.47、19.33、27.72 min.此方法的平均峰面积精密度为2.31％,平均回收率为96.88％;棕榈油、大豆油和亚麻籽油氧化稳定性实验所得水溶液中的短链脂肪酸主要为甲酸和乙酸.此法对深入分析优化油脂氧化稳定性实验具有重要意义.