Spectrophotometric and liquid chromatographic determination of dopamine from pharmaceutical preparations using acetyl acetone as derivatizing reagent

Dopamine [DA] has been determined by spectrophotometry and by liquid chromatography as derivatives of acetylacetone [AA]. The liquid chromatography of DA was carried out in the presence of hydroxyproline [HP], octopamine [OP] and tyramine [TY]. The separation was obtained from Phenomenex C-18 column 5pm [150 x 4.6 mm id] by isocratic elution with methanol: acetonitrile: water [45: 6: 49v/v/v], UV detection was at 320nm. Linear calibration curves were obtained for each with 2.5-40.0 micro gml-1 with detection limits in the range 1.8-80ng injection-1 [10 micro l]. The dopamine was determined in pharmaceutical preparations with coefficient of variation [CV] within 0.7-1.5%