An Effective Application of the Spectrophotometric and Thermodynamic Methods for the Determination of Thiamine Hydrochloride | Book Publisher International
An effective application of the spectrophotometric and thermodynamic methods have been described for the determination of thiamine hydrochloride. The spectrophotometric method was based on charge transfer complexation reaction using thiamine as n-electron donor and 2, 3 dichloro-5,6-dicyano -1,4-benzoquinone (DDQ) as a π-acceptor to form a highly coloured species with 1:1 stoichiometric ratio. The coloured product was quantified spectrometrically at 474nm under the established experimental conditions. Beer’s law was obeyed over the concentration ranges of 5-80μg/ml. The Apparent molar absorptivity was calculated to be 1.08 x 10 3 Lmol -1 cm -1 with the corresponding Sandell sensitivity of 2.68. The Ross equation was used for studying the thermodynamic parameters and result reveals that ∆S was calculated to be between 67.13J/mol and 66.70J/mol, ∆H = -2.87kJ/mol. The association constants were found to decrease from 30°C to 60°C with increase in m...