A spectrophotometric micro determination of pyridoxine hydrochloride by coupling diazometry

ABSTRACT A simple, rapid and sensitive spectrophotometric method has been investigated for determination of microgram amount of pyridoxine hydrochloride .The method is based on the oxidation of 2,4-dinitrophenylhydrazine to produce diazotized2,4-dinitroaniline which will be coupled with pyridoxine hydrochloride in basic medium to form a stable colored product with maximum absorption at 522 nm.Beer'slaw is obeyed over the concentration range of 1-12.5 g.ml-1.The molar absorptivity value is 15214 L.mol-1.cm-1 .The average recovery is 99.09% and relative standard deviation (RSD)is less than 3.2%.The method has been applied successfully for the determination of the studied drug in its pharmaceutical preparation .The obtained result are in agreement with certified value of the pharmaceutical and with the British pharmacopeia method .