Analysis of Ascorbic Acid, Citric Acid and Benzoic Acid in Orange Juice

This Application Note describes a method to quantify an antioxidant (vitamin C) and preservatives (citric acid, benzoic acid) in orange juice. The method was developed on an Agilent 1260 Infinity LC system using an Agilent Poroshell EC-C18 column. Partial method validation was performed in aqueous samples to demonstrate linearity, robustness and precision in area and retention time. The limit of detection (LOD) for benzoic acid was found to be 0.2 μg/mL. During sample recovery studies, greater than 90% recovery was ob¬tained for all three compounds. The method was effectively converted to a short ultra high performance liquid chromatography (UHPLC) method using an Agilent 1290 Infinity LC system. This new method was five times faster with the same LOD for benzoic acid. Both methods can be effectively applied by food manufacturers for quality control of food additives.