A simple fluorometric determination of vitamin C.
A simple and accurate method for determination of vitamin C (ascorbic acid (AsA) and dehydroascorbic acid (DHA)) using 4,5-dimethyl-o-phenylenediamine (DMPD) was investigated. It was found that DMPD is a useful fluorescent reagent. The reaction product of DMPD with DHA showed strong and stable fluorescence (Ex; 360 nm, Em; 440 nm). Fluorometric derivatives were extracted with isobutanol or n-butanol. Extraction with isobutanol was superior to that with n-butanol in terms of specificity, since fluorometric derivatives of keto acids were extracted with n-butanol, together with DHA. The fluorescence intensity of DMPD derivatives was absolutely stable in isobutanol for at least 24 h. The sensitivity of determination of vitamin C was improved by removing several non-fluorometric compounds coexisting in the samples. The derivative derived from AsA was easily separated from those of keto acids by an HPLC method. The determination of vitamin C in natural products was thus improved by extraction and the HPLC method.
Faculty of Pharmaceutical Sciences, Kobe-Gakuin University, Japan.
K
K
Mori
M
M
Kidawara
M
M
Iseki
C
C
Umegaki
T
T
Kishi
D020001:1-Butanol; D001205:Ascorbic Acid / Q000032:analysis*; D000440:Butanols; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003683:Dehydroascorbic Acid / Q000032:analysis*; D010655:Phenylenediamines / Q000737:chemistry; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence / Q000379:methods
D000440:Butanols; D010655:Phenylenediamines; C011793:4,5-dimethyl-1,2-phenylenediamine; C040507:isobutyl alcohol; D020001:1-Butanol; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid