Determination of micro amount of Cobalt (II) by Using Antipyriyl azo pyrogallol

Amal – S-Majeed, Hussein- J-Mohammed


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 1:1 complex with  4-(4- pyrazolon azo) pyrogallol (APAP) as a new reagent is developed . The complex has a maximum absorption at 463  nm and εmax of  1.8 X 104  L. mol-1. cm-1 . A linear correlation (0.05 – 1.5 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 1.45 % ) and accurate (relative error was better than  0.6 %   ) . The effect of diverse ions on the determination of cobalt (II) to investigate the selectivity of the method were also studied . The stability constant of the product was 5.71 X 104  L. mol-1 . The proposed method was successfully applied to the analysis of dust and synthetic mixtures without any preliminary concentration or separation.

Full Text:



  • There are currently no refbacks.