Determination of phenolic acid profiles by HPLC-MS in vegetables commonly consumed in China

This study aimed to establish a precise HPLC-MS approach to determine the concentrations and distribution of major phenolic acids in six categories of vegetables that are commonly consumed in China. We detected 17 phenolic acids within 15 min under optimized conditions. The method showed detection limits varying from 0.008 mg/L to 0.042 mg/L, average recoveries ranging from 71.0% to 110.7%, and a RSD of <= 9.98%. The average concentrations of total phenolic acids followed the order of flower > root > leafy > stem > bean > fruit vegetables. The phenolic acids were more abundant in the leafy, root, and stem vegetables than in the other vegetable samples. Furthermore, the levels of isoferulic acid, p-coumaric acid, and ferulic acid were greater than those of other phenolic acids in the vegetables. Free soluble phenolic acids were the dominant species in all vegetables (P < 0.001), except in the stem vegetables (P < 0.027).