Separation Of Thiamine Research Articles

Simultaneous separation and identification of cyanocobalamin, thiamine, and ascorbic acid on polyoxyethylene sorbitan monooleate-impregnated silica layers with water as mobile phase

A thin-layer chromatographic system comprising a silica layer impregnated with nonionic surfactant (2% Cween 80) as stationary phase and double-distilled water as mobile phase was identified as the most favorable system for mutual separation of the water-soluble vitamins thiamine, cyanocobalamin, and ascorbic acid. The presence of inorganic anions and metal cations as impurities in the sample, the effect of different solvents of the analyte, and the effects of pH of sample and mobile phase were examined for separation of the three-component mixture. It was possible to separate microgram amounts of thiamine from milligram amounts of cyanocobalamin and vice versa. The stability of the mixture of thiamine, cyanocobalamin, and ascorbic acid; the relative standard deviation of the R F values of separated components of the mixture; and the lowest detectable amounts of the three vitamins were determined. The proposed thin-layer chromatographic method is suitable for identification and separation of thiamine, cya...

Specific separation of thiamine from hydrophilic vitamins with aqueous dioxane on precoated silica TLC plates

Summary Specific separation of thiamine hydrochloride from riboflavin, nicotinic acid, calcium D-pantothenate, pyridoxine hydrochloride, cyanocobalamin, and ascorbic acid has been achieved on commercial precoated silica gel 60F254 TLC plates with dioxane-water 1:1 (υ/υ) as mobile phase. The spots were visualized under UV light. The effect of impurities (metal cations and inorganic anions) on the chromatography of thiamine hydrochloride was examined. The detection limit for thiamine hydrochloride was 0.09 μg per spot and the relative standard deviation of the RF value of thiamine hydrochloride in five analyses was 14.99%. The applicability of the method to the identification of thiamine in pharmaceutical formulations was also tested.

Separation of thiamin and its phosphate esters by capillary zone electrophoresis and its application to the analysis of water-soluble vitamins

A capillary zone electrophoresis method for the separation and determination of thiamin and its phosphate esters (free thiamin, thiamin monophosphate, and thiamin pyrophosphate) was developed and optimized. The efficiency achieved with boric acid–sodium tetraborate decahydrate buffer (pH 8.24; 65–8 mM) at an applied potential of 30 kV gave the detection limit (S/N = 3) and the limit of quantitative measurement (S/N = 10) of thiamin and its phosphate esters ranging from 10 −4 to 6 × 10 −4 mM and from 6 × 10 −4 to 1.2 × 10 −3 mM, respectively. The effects of pH on separation and migration times of thiamin and its phosphate esters are described. The method was validated and applied to the quantitative determination of thiamin in commercial tablets containing both a massive and a normal dose of thiamin.

Separation of thiamin and its common degradation and oxidation products by high-performance liquid chromatography.

Separation of thiamin and its common degradation and oxidation products by high-performance liquid chromatography.

Separation of Thiamin, Thiamin Antagonists and Their Phosphate Esters by High-Performance Liquid Chromatography

Abstract Methods are presented for the separation of the phosphate esters of thiamin, oxythiamin or pyrithiamin and the separation of thiamin and oxythiamin by high-performance liquid chromatography. Detection by means of a UV monitor and fluorometer with a post-column oxidation system is described which allows for selective detection of thiochrome, pyrichrome and their respective phosphate esters. Anion exchange and ion-pair reverse phase chromatography are the chromatographic modes of separation.

An improved method for the determination of endogenous thiamine and its phosphate esters in biological material.

Nonphosphorylated thiamine was extracted from tissue homogenates in saline or sucrose into ethylbutylketone-acetonitrile using counter-ion extraction and reextracted into hydrochloric acid. The dried samples were then analyzed by the fluorimetric thiochrome method. Phosphorylated thiamine was treated with Takadiastase to split off the phosphate groups and was thereafter extracted and measured. No column chromatography was needed for the separation of thiamine before the thiochrome assay. A higher accuracy and sensitivity for the thiamine assay was thus achieved.

Separation of thiamine and its derivatives on a Sephadex column

Separation of thiamine and its derivatives on a Sephadex column

Chemiluminescence method for the quantitative determination of vitamin B1 and its phosphate esters in pharmaceutical and biological samples

A large number of methods have been proposed for the quantitative determination of vitamin BI (thiamine): gravimetric [i], fluorometric [2, 3], titrimetric [3], spectrophotometric [4], polarographic [3, 5], and several others [6, 7]. The common deficiency of these methods (apart from fluorometry) is their inadequate specificity. The determination of vitamin B: and its phosphate esters by these methods suffers from interference by various organic and inorganic substances, particularly the products of hydrolysis (thiazole and aminopyrimidine derivatives) and oxidation (thiochrome and thiamine disulfide) of the original substances [8]. This necessitates prolonged and difficult operations for the preliminary separation of thiamine from the impurities by, for example, extraction, adsorption, and chromatographic methods [2, 3, 9-11]. Furthermore the bound forms of natural vitamin BI, such as cocarboxylase, require enzymolysis to thiamine before fluorometric determination [3]. The accuracy of the extant methods for determining vitamin BI varies from 0.08 [6] to 20% [2], depending on the nature of the test sample. The search for rapid, simple, and reliable methods continues to be urgent.