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 103 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 molar absorptivity. Also high values of association constant were
seen which ranged from 500Lmol-1 cm-1 to 1667Lmol-1 cm-1.
The proposed methods were applied successfully to the determination of thiamine
hydrochloride in pure and commercial forms with average recovery of 96.2% ±
0.016. Statistical comparison of the results were performed using student’s
t-test and f-test at 95% confidence level
Author Details:
Gloria Nwanisobi
Department
of Pure and Industrial Chemistry, Nnamdi Azikiwe University, Awka, Nigeria.
Pius Ukoha
Department
of Pure and Industrial Chemistry, University of Nigeria, Nsukka, Nigeria.
View Volume: https://doi.org/10.9734/bpi/mono/978-93-89246-76-6
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