Spectrophotometric (flow injection and batch) methods for the determination of some catecholamine drugs in pharmaceutical preparations

Abstract

A batch and flow injection ( FIA) Spectrophotometric methods have been
investigated for the determination of some catecholamine drugs in aqueous solution and in
pharmaceutical preparations. The methods are based on the reaction of catecholamine
drugs ( methyl dopa (I) , adrenaline (П) and dopamine (Ш)) with N,N-dimethyl aniline in
the presence of potassium metaperiodate in neutral media to form an orange water soluble
stable dye that has a maximum absorption at λmax 478,493 and 482nm for (I), (П) and (Ш)
respectively . linearity was in the range of 1-40,0.5-30 and 0.5-20 μg.ml-1 with a limit of
detection ( signal /noise=3) of 0.39 ,0.34 and 0.36 μg.ml-1 for (I), (П) and (Ш) respectively
by batch method and 5-60,5-100and 5-100 μg.ml-1 with a limit of detection of 0.90,0.88
and 1.71 μg.ml-1 for (I), (П) and (Ш) respectively by FIA method .The effect of chemical
and physical parameters have been carefully considered and the proposed procedures were
successfully applied to the determination of some catecholamine drugs in pharmaceutical
formulation