| 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. |
