Abstract
Spectrophotometric Determination Of Certain Vicinal Dihydroxybenzene Derivatives With Isoniazid
A simple sensitive and accurate spectrophotometric method is developed for the determination of vicinal dihydroxybenzene derivatives [pyrocatechol (PCL), dopamine (DPH), levodopa (LDP) and methyldopa (MDP)] using pyridine-4-carboxylic hydrazid (isoniazid) in alkaline medium. Beer's law of the coloured species is obeyed in the range 1.2 to 12μg/ml at the maximum absorption of 480 nm. The molar absorptivity found to be 1.4312 x 104, 1.5015 x 104, 1.0924x104 and 7.2163x1031/mol/cm for DPH, PCL, LDP and MDP respectively. The proposed method is successfully applied for the determination of DPH, LDP and MDP in injections and tablets of pharmaceutical preparation. The reliability of these methods is established by parallel determination with the reported and official methods.
