Determination of benzoic acid and sorbic acid in seasoning by capillary electrophoresis with a new triethylamine aminated polychloromethyl styrene nanolatex coated capillary column

Abstract

In this work, a method for the determination of benzoic acid (BA) and sorbic acid (SA) in soy sauce and vinegar was developed by field-amplified sample stacking open-tubular capillary electrochromatography (FASS-OT-CEC) with a new triethylamine aminated polychloromethyl styrene nanolatex coated capillary column (ccc-TEAPL). The ccc-TEAPL was characterized with steady electroosmotic flow (EOF) values of ca. −16.7–19.8 × 10⁻⁵ cm² V⁻¹ s⁻¹. Under the optimized conditions, BA and SA were well separated within 5 min (R_s > 1.5), and the limits of detection were 30 ng mL⁻¹ and 5 ng mL⁻¹, respectively. The recoveries were between 98.0 and 101.0%. These results demonstrate that the developed FASS-OT-CEC method is simple, rapid, sensitive and practical for the determination of BA and SA in the soy sauce and vinegar samples.