STUDY ON THE METHODS FOR QUANTITATIVE ESTIMATION OF ASCORBIC ACID IN URINE
- VernacularTitle:尿中抗坏血酸测定方法的研究
- Author:
Benmou CHEN
;
Chien MIAO
;
Chengtsai KUO
- Publication Type:Journal Article
- From:
Acta Nutrimenta Sinica
1956;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
It has been proved chromatographically that the substances in human urine interfere 2,6-dichlorophenol indophenol visual titration method are mainly thiosulfates, cysteine and an unknown substance with Rf of 0.5 (Rf of ascorbic acid = 0.28). Ketonic substances present in urine interfere the ascorbic acid estimation with 2,4-dinitrophenylhydrazine colorimetric method. The amount of these interfering substances present in human urine is usually high, so that erroneous results are obtained with both methods, even in the case of large amount of ascorbic acid in the sample.Formaldehyde at pH 2.0 can not condense with ascorbic acid quantitatively, so that the results obtained by formaldehyde condensation method are considerably lower than that obtained with Kuo and Chen's filter paper partition chromatographic method.Our results indicate that the last mentioned method is the most convenient and accurate one for the quantitative analysis of ascorbic acid in urine.
