High-performance liquid chromatographic method for the determination of l-ascorbic acid and d-isoascorbic acid

Properties of poly-aminophenylboronate coatings in capillary electrophoresis for the selective separation of diastereoisomers and glycoproteins

“…Moreover, at pH values around the pK of boronic acid, no improvement in the separation were observed. Thus, it is hypothesised that the separation of ascorbic and isoascorbic acid on poly-APBA column does not depend on the formation of boronate esters, most likely an analyte-amine interactions might be responsible of the separation, as already described for chromatography [26].…”

“…As recently indicated in a NMR study by Obi et al [30], such separations results in the formation of different complexes: ascorbic acid forms a 6-member ring complex with borate, while isoascorbic acid forms a 5-member ring complex with borate. A different principle is implicated in the HPLC separations reported where the separation was achieved on aminophases [26], as well as on styrene-type reverse phases [27].…”

Analysis of Vitamin C (ascorbic acid) Contents packed fruit juice by UV-spectrophotometry and Redox Titration Methods

“…Due to the destructive oxidation hydrolysis at higher PH, this results in the opening of the lactone ring of the ascorbic acid and loose the vitamin activity. These processes naturally occurre in fruits, and some amounts ofdiketogulonic acid is present in the fruits (Geigertj et al, 1981). As the diketogulonic acid has keto group, it should give the osazone with DNPH as that of ascorbic acid and should give the colored complex on treatment with 85% H 2 SO 4 .…”

Ascorbic acid determination in serum and aqueous humour by high‐performance liquid chromatography

“…In such cases, HPLC is an excellent tool for analysis. There are several reports describing successful application of HPLC to determine AA in foods and multivitamin products using reverse phase, (Sood et al 1976;Wills et al 1977) (Sood et al 1976;Wills et al 1977;Geigert et al 1980) detection. Electrochemical detection is ectremely sensitive, but requires equipment which is not available in most laboratories.…”