Spectrofluorimetric Determination of Some Water-Soluble Vitamins

Abstract

Two simple and sensitive spectrofluorimetric methods were developed for determination of three water-soluble vitamins (B1, B2, and B6) in mixtures in the presence of cyanocobalamin. The first one was for thiamine determination, which depends on the oxidation of thiamine HCl to thiochrome by iodine in an alkaline medium. The method was applied accurately to determine thiamine in binary, ternary, and quaternary mixtures with pyridoxine HCl, riboflavin, and cyanocobalamin without interference. In the second method, riboflavin and pyridoxine HCl were determined fluorimetrically in acetate buffer, pH 6. The three water-soluble vitamins (B1, B2, and B6) were determined spectrofluorimetrically in binary, ternary, and quaternary mixtures in the presence of cyanocobalamin. All variables were studied in order to optimize the reaction conditions. Linear relationship was obeyed for all studied vitamins by the proposed methods at their corresponding lambda(exc) or lambda(em). The linear calibration curves were obtained from 10 to 500 ng/mL; the correlation ranged from 0.9991 to 0.9999. The suggested procedures were applied to the analysis of the investigated vitamins in their laboratory-prepared mixtures and pharmaceutical dosage forms from different manufacturers. The RSD range was 0.46-1.02%, which indicates good precision. No interference was observed from common pharmaceutical additives. Good recoveries (97.6 +/- 0.7-101.2 +/- 0.8%) were obtained. Statistical comparison of the results with reported methods shows excellent agreement and indicates no significant difference in accuracy and precision.

Multicomponent Analysis of Fat- and Water-Soluble Vitamins and Auxiliary Substances in Multivitamin Preparations by qNMR

“…16 Moreover, advanced chemometic techniques were recently applied to vitamin mixtures to mathematically resolved UV−vis spectra of fat-and water-soluble vitamins. 17,18 It should be mentioned that the common disadvantages of existing methods for vitamin analysis include time-consuming sample preparation (e.g., extraction) to remove endogenous interferences from the matrix, high solvent volume, demand of complex multivariate methods, or the necessity of supercritical conditions to cover all vitamin ranges in a single analytical run. 17−19 Apart from active ingredients (vitamins), a number of accompanying substances (sweeteners, acidifiers, and antioxidant agents) can be found in multivitamin preparations.…”

Stability-Indicating Photochemical Method for the Assay of Thiamine by Spectrophotometry

“…It is extensively used as a component of single vitamin B complex and multivitamin preparations [2][3][4]. Several analytical methods, including UV and visible spectrophotometric and multivariate analysis [5][6][7], fluorimetric [8][9][10][11][12][13][14][15][16][17][18][19][20][21], high performance liquid chromatography (HPLC) [22][23][24][25][26][27][28][29][30][31][32][33][34][35], UHPLC/MS-MS [36], turbidimetric and nephelometric [37], amperometric [38], and voltammetric methods [39][40][41][42][43][44][45], have been used for the assay of thiamine and its salts in pharmaceutical preparations, food materials and biological fluids. Some of these methods have previously been reviewed [46][47][48]…”

“…iamine undergoes chemical [1,8,9,11,14,16,17,19,[51][52][53][54] and photochemical oxidation [55,56] to form thiochrome (TC) which exhibits a blue fluorescence (440 nm). is has been made as the basis of fluorimetric determination of TH [8,9,11,14,16,17,19,[54][55][56][57][58][59][60].…”

A simple spectrophotometric method for determination of thiamine (vitamin B1) in pharmaceuticals

“…For example Khan [15] found the linear range from 0.026-16.830 µg/mL, r = 0.9964, RSD = 1.75%, LOD = 0.015 µg/mL, Mohamed [16] found that linear range from 10-500 ng/mL , r = 0.9991, RSD = 0.46-1.02%, Recovery = 97.6% and Szpikowska-Sroka [17] found the linear range from 0.4-2.4 µg/mL , r = 0.9998 and LOD = 0.19 and 0.26 µg/mL. 0.9998 * y = a + bx; y: the transmittance of concentration, x: the concentration in µg/mL.…”

“…Two simple and sensitive spectrofluorimetric methods were developed for determination of thiamine by oxidized to thiochrome by iodine in an alkaline medium [16] or oxidized with potassium iodate(V) to the colourless product and a stoichiometric amount of iodide ions was formed. The latter reacted with the excess of iodate(V) ions in acidic medium, to form free iodine which oxidized leucocrystal violet to the crystal violet dye [17].…”