Method For Determination Of Thiamine Research Articles

Application of Spectrophotometric Methods for the Determination of Thiamine (VB1) in Pharmaceutical Formulations Using 7-Chloro-4-Nitrobenzoxadiazole (NBD-Cl)

Simple, swift and sensitive method for Spectrophotometric determination of thiamine (VB1) in pharmaceutical tablets has been described. The proposed method is based on the reaction of thiamine (VB1) and 7-Chloro-4-nitrobenzoxadiazole (NBD-Cl) at alkaline medium (pH 10.5) to develop a deep brown adduct that bears maximum absorption at 434 nm. Beer’s law is obeyed in the concentration range 5-35 µg/ml of thiamine at the selected wavelength. Under optimized reaction conditions, the linear regression coefficients were a=0.033, b=-0.009, and r2=0.999 calculated for the general equation of the calibration curve (y = ax + b). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.667µg/ml and 2.020µg/ml respectively. The method has been successfully applied to the determination of thiamine (VB1) in pharmaceutical formulations, and can be used as an alternative of the existing sophisticated method used in drug laboratories and factories.

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

A simple spectrophotometric method has been described for the determination of thiamine. The method is based on the precipitation of sulphur as barium sulphate using barium chloride after oxidation of thiamine by sodium hydroxide and hydrogen peroxide. Beer's law was obeyed over the concentration range from 2-32 µg/mL thiamine. The average of standard deviation was 1.18×10 -2 ; standard error, 5.20×10 -3 ; relative standard deviation, 0.51%; relative standard error, 5.40×10 -3 ; 95% coefficient, 1.48×10 -2 ; the limit of detection, 0.41 µg/mL; the limit of quantification, 1.38 µg/mL and recovery, 100.03% thiamine. Finally, the developed method was applied to the determination of thiamine in pharmaceutical formulations.

A simple and sensitive analytical method for the determination of thiamine in pharmaceutical preparations

A simple and sensitive method for spectrophotometric determination of thiamine with leucocrystal violet was elaborated. Spectrophotometric quantification based on the following reaction sequence: thiamine was 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. The absorbance of the crystal violet dye formed was measured at pH 4.1 ± 0.1 and 589 nm. The measured absorbance obeyed Beer’s law over the thiamine concentration range 0.4-2.4 μg/mL. The linear regression coefficients were a = 0.3339, b = −0.0001, and r = 0.9998 (for the general form of the linear equation y = ax + b). The apparent molar absorptivity of the coloured compound was 1.12 × 105 L/mol cm for thiamine. The limit of detection and limit of thiamine determination were found to be 0.19 and 0.26 μg/mL, respectively. Optimum reaction conditions providing maximum and constant absorbance were optimized. The procedure was successfully used to the determination of vitamine B1 in pharmaceutical formulations. The obtained results were compared with those obtained by the method proposed by Polish Standard.

A Cloud Point Extraction-Spectrofluorimetric Method for Determination of Thiamine in Urine

A simple and efficient cloud point extraction-spectrofluorimetric method for the determination of thiamine in human urine is proposed. The procedure is based on the oxidation of thiamine with ferricyanide to form thiochrome, its extraction to Triton X-114 micelles and spectrofluorimetric determination. The variables affecting oxidation of thiamine, extraction and phase separation were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 2.5-1000 ng . The limit of detection was 0.78 ng of thiamine and the relative standard deviation for 5 replicate determinations of thiamine at 400 ng concentration level was 2.42%. Average recoveries between 93-107% were obtained for spiked samples. The proposed method was applied to the determination of thiamine in human urine.ꤠ돀遠�⨀堘�⨀袒�⨀脠돐ꢒ�⨀ࢷ�⨀낒�⨀夠뎐／ࠀ⣕�⨀愁덀态Ȁ胮傫i傫Āā?뤞덐塲�⨀퀿ﶖ⨀
⩈ﶖ⨀똗㠑?⨀傗ꐂ㠑?⨀႘ꐂ餂돐リ�⨀ꢶ�⨀頿ﶖ⨀뤁뎀／ࠀ끶�⨀礁덐态Ȁ瀂莒莒Āā뤀댐�⨀螑㌄죞�⨀䀠�⨀ࡡ�⨀Ă頓煥獣愠獵扨敡瀀ｿｿｿｿ⡷�⨀⡷�⨀ꤠ돀遠�⨀堘�⨀႘�⨀脠돐゘�⨀ࢷ�⨀㢘�⨀夠뎐／ࠀჭ�⨀愁덀态Ȁヮ䞤烯墦Āā輀

Flow injection fluorimetric determination of thiamine and copper based on the formation of thiochrome

The reaction, involving the oxidation of thiamine by copper(II) in basic solutions to fluorescent thiochrome, has been adapted to the determination of thiamine by flow-injection analysis. Linear calibration graphs are obtained between 0.30 and 6.02 μg/ml with a sampling rate of 50 samples/hr and a relative standard deviation of 0.53%. This reaction has also been adapted to the determination of copper(II) over the range 0.5–5.0 μg/ml. The applicability of both methods for determination of thiamine and copper is demonstrated by investigating the effect of potential interferences and by the analysis of real samples (pharmaceuticals for thiamine and ores and alloys for copper).

Simultaneous Determination of Thiamine and Riboflavin in Foods by Liquid Chromatography

Recent methods for determination of thiamine (thiochrome) and riboflavin by liquid chromatography (LC) are outlined and discussed, and a new method allowing the simultaneous determination of these 2 vitamins by using a single fluorescence detector is described. This system involves an ODS 5 micron ultrasphere column and a pH 7.5 mobile phase composed of 0.005M tetrabutyl ammonium phosphate in methanol-water (20 + 80).

Comparison of Manual and Benzenesulfonyl Chloride-Semiautomated Thiochrome Methods for Determination of Thiamine in Foods

A semiautomated procedure was used to measure the fluorescence of sample extracts before and after the addition of benzenesulfonyl chloride (BSC). Addition of BSC inhibited thiochrome formation and provided a more representative blank based on the fluorescence of all the reactants except thiochrome. Thiamine standard was added to each sample extract so that thiamine concentration could be calculated after correcting for sample matrix effects on thiochrome fluorescence. Twenty food products were analyzed using this method, and the results were compared with those obtained using the manual AOAC method. The mean percent recoveries and standard deviations were 100.2 +/- 5.3 and 101.1 +/- 10.1 for the BSC-semiautomated and the AOAC manual methods, respectively. Replicate analyses using the BSC method gave an average coefficient of variation of 2.8%. Linear regression analysis showed that the BSC method gave higher values, with a mean increase of 14.8%, than those obtained using the manual method. Sixty-four percent of this difference was due to elimination of the column purification step and 36% was due to correcting for sample matrix effects on thiochrome and blank fluorescence. The BSC method provides a rapid, accurate, and reproducible method for thiamine assay in different food products, especially for those foods with low thiamine levels.

An Autoanalytical Method for Determination of Thiamine, Thiamine pyrophosphate and Thiamine disulfide in Blood and Urine

An Autoanalytical Method for Determination of Thiamine, Thiamine pyrophosphate and Thiamine disulfide in Blood and Urine

Methods for Determination of Thiamine in Blood and Tissues with Observations on Relative Contents

SummaryWith the aid of these methods it has been shown, in the rat, that the thiamine concentration in the blood parallels that in the tissues, and both reflect the intake.