Simultaneous Determination of Binary Mixtures Cobalt“- Nickel2*& Iron2*- Cobalt“ by H-Point Standard Addition Method

Abstract

The study describes the optimization of an analytical procedures for the simultaneous detemination of binary metal ions pair in complex samples. Iron and cobalt are metals, which appear together in many real samples, both natural and artificial, so it is very important to develop reliable, fast and sensitive methods for analysis of iron and cobalt in environmental and biological samples. Simultaneous determination of iron and cobalt was carried out by H-point standard addition method (HPSAM). The proposed method aimed to solve the overlapping spectrum of Fer’ and Co“ complexes without the need to solve simultaneous equation. Using l-(2- pyridylazo)-2-naphthol (PAN) as chromogenic reactant with Fe“ and C02" fom1ing soluble brown and green colored complexes respectively. Using PAN as chromogenic 4- reagent and at pH 5.8 Beer‘s law was obeyed at 592 nm for Fez and 473 nrn for Co“ in the concentration range 5.0><10‘5 to 5.0><l0'5 mg/L. The absorbance at the selected wavelength pair,630 nm and 660 nm were monitored with addition of standard