22 research outputs found
Ascorbic, Dehydroascorbic and Isoascorbic Acid Simultaneous Determinations By Reverse Phase Ion Interaction Hplc
Detection was by UV absorbance (after pre-column derivatization of dehydroascorbic acid with 1,2-phenylenediamine). When absent, isoascorbic acid could be used as internal standard. Isocratic separation was accomplished in 11 min using the eluent, methanol-water (5:95, v/v) containing potassium dihydrogen phosphate (50 mM) and the counterion hexadecyltrimethylammonium bromide (5 mM). Sample preparation steps using Sep-pak C18 cartridge were minimal. Ten ppm could be detected for each compound with good reproducibility (c.v. < 2%). The method was used to determine vitamin C content in selected foods and beverages
Ascorbic, Dehydroascorbic and Isoascorbic Acid Simultaneous Determinations by Reverse Phase Ion Interaction HPLC
EFFECT OF DIETARY VITAMIN C LEVELS ON THE RATE OF BROOD PRODUCTION OF FREE-FLYING AND CONFINED COLONIES OF HONEY BEES
International audienc
LEVELS OF THIAMINE AND ITS ESTERS IN BEE COLLECTED POLLEN USING LIQUID CHROMATOGRAPHY AND ROBOTICS
International audienc