Determination of the stability constant of Cobalt (ІІ) – Piroxicam complex by spectrophotometery

Document Type : Research Paper


Not mentioned


In this work, a new spectrophotometric method for the determination of trace amount of Cobalt (ІІ) ion
was investigated and the stability constant of the related complex was evaluated 2.174 × 104. In the Cobalt
(ІІ)-piroxicam complex, the maximum absorbance wavelength is 570 nm and the linearity of calibration
curve was investigated (5-10 ppm). The relative standard deviation for seven replicate experiments is
0.5292 percent. The accuracy is 0.15 percent and limit of detection is 1.19 ppm. The analytical sensitivity
allows us to detect the concentration difference of 0.06 ppm with reliable level of confidence. The ligand to
metal ratio was determined (1:1) by the continuous variation method. The above spectrophotometric
method was optimized in terms of pH, temperature, time, ligand concentration and ionic strength. This
method is tolerant against several external matters, which means high selectivity.