Determination of Total Vitamin C in Various Food Matrixes by Liquid Chromatography and Fluorescence Detection
Abstract A liquid chromatographic method was developed for quantitation of total vitamin C content in various food matrixes. The method includes extraction with 3% mete-phosphoric acid-acetic acid and oxidation of ascorbic acid to dehydroascorbic acid with Norit, followed by reaction with ophenylenediamine to form a fluorescent derivative. The fluorescent derivative is separated on a µBondapak C18 (10 µm) column with methanol-water (55 + 45) and detected fluorometrically. This method is demonstrated to be suitable for several sample matrixes, including complex matrixes of canned corn, potatoes, green beans, potato chips, and cereals. Other products analyzed include infant formula, medical foods, fruit juice, and multivitamin tablets. Recoveries are in the range of 90-108%. Comparison of results with those by the AOAC fluorometric method shows excellent agreement.