ultrahigh-performance liquid chromatography-ion chromatography system for the simultaneous determination of vanillin, ethyl vanillin, and inorganic anions in food samples

A simple hyphenated ultrahigh-performance liquid chromatography-ion chromatography (uhplc-ic) column-switching analytical method was developed for the simultaneous determination of vanillin, ethyl vanillin, and six inorganic anions (i.e., bro3 −, cl−, no2 −, clo3 −, no3 −, and so4 2−) in food samples. a fast ultrasound-assisted extraction method with a solvent of acetonitrile/water (3:2, v/v) was utilized. methanol/water (30:70, v/v) and 13 mmol/l koh were used as eluents for separation. an ionpac ag19 column was applied as the concentration column for the online pre-concentration of anions. the c18 column functioned as the analytical column for the separation of organic compounds and as the online matrix elimination column for inorganic anions. the effects of the analytical variables were systematically studied and optimized. under optimal experimental conditions, the limits of detection for vanillin, ethyl vanillin, and inorganic anions ranged from 6.2 to 27 μg/l. the relative standard deviations of the retention time and peak area were less than 1.36 and 3.05%, respectively. the spiked recoveries were 95.73–107.3%. experimental results demonstrated that the hyphenated uhplc-ic column-switching analytical method could be successfully applied for the analysis of vanillin, ethyl vanillin, and inorganic anions in food samples.