Trace Multi-ions Concentration Detection in Zinc Sulfate Solution Based on A Novel Characteristic Wavelength Selection Method

Abstract

For detecting the trace multi-ions concentration in zinc sulfate solution with UV-Vis spectrophotometry, high concentration of zinc ion will result in masking effect and suppression differential problem in partial wavelengths in full band spectrum of the metal ions. To extract high sensitivity wavelengths as well as remove severe masked wavelengths and wavelengths which is inherited different seriously, a novel method was proposed to select characteristic wavelength based on multi-indexes fusion of sensitivity, sensitivity ratio and interval correlation coefficient. Finally, with the selected characteristic wavelength, partial least squares model of the trace multi-ions concentration was established. The average relative error of cobalt and copper ions were 5.15% and 3.28% respectively. It shows that the multi-indexes fusion method could solve the problem that characteristic wavelength is difficult to select in the progress of detecting the trace multi - ions concentration in zinc sulfate solution.