ABSTRACT
The conditions of chromatographic separation allowing the isolation of L-ascorbic acid from its products of decomposition and other accompanying substances in the determined pharmaceutic preparation and plant materials were established. The isolated L-ascorbic acid was signed by the extractive - spectrophotometric method using coupled redox-complexation reactions with iron(III), 1, 10 phenantroline and bromophenol blue system. The analitycal procedure allowing the evaluation of durability of vitamin С in multivitamin „Vitaral” preparate was described. The procedure was used also for the evaluation of the loss of L-ascorbic acid in the parsley and lovage in the process of drying and storage.