title: Spectrophotometric determination of pyridoxine hydrochloride [correction of hydrochlorine] pharmaceutical preparations and foods.
abstract: An easy and sensitive spectrophotometric assay of pyridoxine is described. The procedure is based on formation of an azo dye by the reaction of pyridoxine with diazotized 2,4-dinitroaniline followed by the reaction of the dye with Hg2+ ions to form a stable complex with maximum absorbance at 545 nm. The system obeys Beer's law for 4-75 micrograms pyridoxine hydrochloride in an overall aqueous volume of 25 mL (correlation coefficient, 0.9998). On extraction into 5 mL butan-1-ol, the system obeys Beer's law in the range 0.8-15 micrograms pyridoxine hydrochloride at 545 nm. The color is stable for 60 min in both aqueous and organic phases (molar absorptivity, 3.7 x 10(4) L/mol.cm; coefficient of variation, 3.1%, n = 10). The pyridoxine contents of pharmaceutical preparations, a processed foodstuff, and 2 rice samples were determined by using the proposed method. Assay reliability was established by recovery studies and parallel determination using a reported method.
authors.affiliation: Indian Institute of Technology, Department of Chemistry, Madras, India.
authors.forename: K
authors.initials: K
authors.lastname: Srividya
authors.forename: N
authors.initials: N
authors.lastname: Balasubramanian
mesh_terms: D005504:Food Analysis; D012275:Oryza / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000032:analysis*; D011736:Pyridoxine / Q000032:analysis*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013997:Time Factors
chemical_list: D004364:Pharmaceutical Preparations; D011736:Pyridoxine