Muthanna Journal of Pure Sciences – MJPS
Vol.3 – No. 2 / October 2016
Shaimaa. H. Mallah
Chemistry Department/ Faculty of Science/ AL-Muthanna University
A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of cobalt (II). The method is based on the formation of a 1:2 complex with 1-(4′- antipyryl azo) 2,7-naphthalendiol (1-APANDOL) as a new reagent is developed . The complex has a maximum absorption at 542 nm and εmax of 1111×104 L. mol-1.cm-1. A linear correlation (0.1–2.5 μg. mL-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of cobalt (II) were tested . The results obtained are both precise (RSD was better than 0.44 %) and accurate (relative error was better than 0.35 %). The stability constant of the product was 1.6 ×108 L. moL-1.