A green colorimetric method using guava leaves extract for quality control of iron content in pharmaceutical formulations

Abstract

© 2019, Malaysian Society of Analytical Sciences. All rights reserved. A cost-effective and environmentally friendly approach using a simple micro-volume colorimetric method with non-synthetic reagent from plant extracts has been proposed. The crude aqueous extracts from dried guava leaves were utilized as an alternative natural reagent for quantification of iron. The method was based on the measurement of a dark brown complex formed by the reaction between Fe(III) and the crude aqueous extracts in acetate buffer pH 4.5 at 562 nm. The optimum conditions for the extraction parameters such as type of solvent, extraction time and mass of dried plant were investigated. Under the optimum conditions, a linear calibration graph in the range of 1.0-10.0 mg L-1 Fe(III) was obtained with limits of detection and quantification of 0.30 and 1.0 mg L-1 Fe(III), respectively. Relative standard deviations of 2.6 and 2.1% were achieved for 2.0 and 4.0 mg L-1 Fe(III) (n=7), respectively. The developed method was successfully applied to quality control of iron in antianemic drug samples. The results are in good agreement with those obtained by the FAAS method at the 95% confidence level. High percentage recoveries between 93 and 99% were obtained.