Spectrophotometric Determination of Trace Amount of Nickel(II) in Tea Leaves Sample by Using Antipyriyl azo-2,7-naphthalendiol as New Reagent

Abstract

Abstract:A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of nickel(II). The method is based on the formation of a 1:2 complex with 1-(4 ′ -pyrazolon azo) 2,7-naphthalendiol (1-APANDOL) as a new reagent is developed . The complex has a maximum absorption at 514 nm and ε max of 2.0x10 4 L mol -1 cm -1 . A linear correlation (0.1-2.0 μg mL -1 ) was found between absorbance at λ max and concentration. The accuracy and reproducibility of the determination method for various known amounts of nickel(II) were tested. The results obtained are both precise (RSD was better than 0.63%) and accurate (relative error was better than 0.2%). The effect of diverse ions on the determination of nickel(II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0.13x10 8 L mol -1 . The proposed method was successfully applied to the analysis of synthetic mixtures and tea sample without any preliminary concentration or separation.