Determination of Cobalt and Nickel by PAR Spectrophotometry

The investigation of simultaneous determination of cobalt and nickel by 4-(2-pyridineazo) resorcinol(PAR) spectrophotometry was carried out.In the butter solution of NaAc-HAc at pH=5,the cobalt and nickel can form the stable complexes with the color reagent of PAR.The absorption spectra of complexes were seriously overlapped,two wavelengths for 508,568nm were selected as determining wavelength of cobalt and nickel after many tests,and dual wavelength linear regression method was set up to use for simultaneous determination of cobalt and nickel.The method is simple,rapid with high sensitivity.