IC Determination of Additive Propionate in Food

A method of IC was proposed for the determination of the additive propionate in food. The sample was extracted with water by distillation. The propionate and interfering ions in the extract were separated on IonPac AS11-HC (250 mm ×4 mm) column with IonPac AG11 (250 mm ×4 mm) as guard column, by gradient elution with KOH solution of different concentrations as mobile phase and detected by conductivity detector. Linear relationship between values of peak area and mass concentration of propionic acid was kept in the range of 20.00-40.00 mg·L-1, with detection limit (3S/N) of 1.00 mg·kg-1. The present method was applied to the determination of propionate in sample of vermicelli, giving values of recovery ranged from 91.3%-96.2%, and values of RSD′s (n=6) ranged from 0.5%-1.2%.