High-resolution/higher-order derivative spectrophotometry for determination of ternary mixtures of B-complex vitamins in pharmaceuticals

Abstract.

A method for the determination of ternary mixtures of the B-complex vitamins B6, B1 and B12, by fifth-derivative spectrophotometry is described. The procedure works without any separation step or solving of equations. Beer's law has been valid up to 100 μg/mL for each compound. Detection limits at p=0.01 level of significance have been calculated to 0.009, 0.054 and 0.005 μg/mL and determination limits of 0.027, 0.19 and 0.017 μg/mL have been found for the respective vitamin. The procedure has been successfully applied to the simultaneous determination of vitamins B6, B1 and B12 in synthetic mixtures and in commercial injections and tablets for these drugs (without other vitamins) with a high reliability and repeatability.