Simultaneous Determination of Benzoic Acid and Sorbic Acid in Food Products by Capillary Electrophoresis

Abstract

In this work, a rapid and easy capillary electrophoretic method for simultaneous determination of benzoic acid and sorbic acid in food samples using direct UV detection was reported. The separation of acids was achieved in fused silica capillary at 28 kV. 20 mM borate buffer at pH 9.3 was used as running buffer; cinnamic acid was chosen as internal standard for quantification. Under the optimal separation conditions benzoic acid and sorbic acid were detected in 3.1 min. The linear ranges were between 0.005-0.4 mM. The correlation coefficients for each calibration curve were calculated as 0.999. The reproducibility of peak area and migration time for each acid were less than 3% (R.S.D.). The limits of detection were found 0.405 g/mL for benzoic acid and 0.415 g/mL for sorbic acid. The limits of quantification were 1.35 μg/mL and 1.38 μg/mL respectively.