Pyridoxine assay methods

Yagi, T., Murayama, R., Do, H.T.V., Ide, Y., Mugo, A.N., and Yoshikane, Y., 2010b. Development of a simultaneous enzymatic assay method for all six individual vitamin Bg forms and pyridoxine-p-glucoside. Journal of Nutritional Science and Vitaminology. 56 157-163. 

Among various methods reported, we wish to describe an assay technique with Saccharomyces carlsbergensis 4228. This yeast had been used by Atkin et al. (All) for the determination of vitamin B6. We have omitted inositol from the medium and have added an excess of pyridoxine (S19). The composition of the medium is given in Table 8. The method has an accuracy of 0.1 mpg/ml. 

Several colorimetric assays have been developed for pyridoxine. The U.S.P. method (4) for the determination of pyridoxine HC1, is based on coupling of pyridoxine with 2,6-dichloroquinone chloroimide to give a blue color, according to the method described by Kuhn and Low (121). The absorbance of the blue color is measured at 650 nm and compared with standard solutions. The... 

Wada and Snell (150) have developed a method for the assay of pyridoxine and pyridoxamine phosphate, based on enzymatic oxidation to pyridoxal which is allowed to react with phenylhydrazine. 

Several B vitamins, including folic acid, niacin, pyridoxine, and pantothenic acid, are routinely determined using microbiological assays, details of which can be found in the AOAC Official Methods of Analysis. Standard methods for thiamine determination using fluorimetric detection are also detailed in the AOAC methods in addition, LC techniques are now being used routinely for thiamine and other B vitamins, e.g., riboflavin. 

Coverage includes B vitamins and folate in the context of a historical background, disease, cardiovascular effects and the importance of vitamins in biochemistry as illustrated by a single vitamin. Thereafter there are chapters on the chemistry and biochemistry of thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate and cobalamin. Methodical aspects include characterization and assays of B vitamins and folate in foods of all kinds, dietary supplements, biological fluids and tissues. The techniques cover solid-phase extraction, spectrofluorimetry, mass spectrometry, HPLC, enzymatic assay, biosensor and chemiluminescence. In terms of fimction and effects or... 

In 2000, Chen et al. [8] developed a method based on CE-ECD for the determination of melatonin and pyridoxine in pharmaceutical preparations for health-caring purposes. CE was performed in a 25 mM phosphate buffer (pH 8.3). The two compounds were separated and detected within 12 min. The working electrode used was a carbon electrode operated in a wall-jet configuration. Excellent linearity was observed between peak current and concentration of analytes with the detection limits ranging from 1.3 to 2.7 pM. The proposed method was successfully applied to analyze the actual samples with satisfactory assay results. 

Although the fluorimetric method given above is applicable to this preparation, Foster and Murfin successfully applied alginic acid to the quantitative separation of aneurine, nicotinamide and pyridoxine when present in admixture, with subsequent assay of these separated components spectrophotometrically. Preparation of the alginic acid is described under Nux Vomica (p. 461). 

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