Utilization of 2-Nitro-6-(thiazol-2-yldiazenyl)phenol for Spectrophotometric Determination of Trace Amounts of Copper(II) in Water Samples

A simple ultra sensitive and fairly selective non extractive spectrophotometric method for the determination of copper using 2-nitro-6-(thiazol-2-yldiazenyl) phenol (NTDP) has been developed.. The method is based on the color reaction of copper with NTDP at pH 7.1 buffer. The optimal reaction conditions (e.g., reagent concentration, pH and effect of time and temperature) were studied and the analytical characteristics of the method (e.g., limit of detection, limit of quantification, and linear ranges) were obtained. Linearity was obeyed in the range of 0.1-5.0 µg/mL of copper(II) ion and the detection limit of the method was 3.0 ng/mL. The relative standard deviation (RSD) and relative error for six replicate measurements of 2.0 µg/mL Cu(II) were 0.76 % and 1.34 %, respectively. The interference effect of some anions and cations was also tested. The method was applied to the determination of copper(II) in water samples.