Electrochemical Determination of Ascorbic Acid and Isoascorbic Acid in Ground Meat and in Processed Foods by High Pressure Liquid Chromatography

Some researchers have reported that ascorbic acid (AA) and/or isoascorbic acid (IAA) was detected in ground meat, prompting our laboratory to undertake a small survey to determine if the addition of AA and IAA to ground meats was common practice. The study was expanded to include dairy products, luncheon meats, meal replacements, diet products, vegetable and fruit drinks, and beverages. Detection of AA, dehydroascorbic acid (DHAA), IAA, and dehydroisoascorbic acid (DHIAA) was done by HPLC with electrochemical detection. Two PLRP-S columns cooled to 5°C were used with a 20 mM sodium phosphate monobasic, monohydrate (NaH2PO4-H2O) and 0.17% (v/v) metaphosphoric acid (HPO3) mobile phase, pH 2.2. The limit of detection was 0.2 mg/100 g sample. Generally, variable amounts of AA and DHAA were detected, although in some foods, traces or no vitamin C was detected while only processed meats and ice tea contained IAA.