Overlapped peaks resolution for linear sweep polarography using Gaussian-like distribution
(1. School of Information Science and Engineering, Central South University, Changsha 410083, China;
2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract: A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn(II) and Co(II), coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares (NWLS). Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn(II) and Co(II).
Key words: zinc hydrometallurgy; Gaussian-like distribution; overlapped peaks resolution; multi-resolution wavelet decomposition; nonlinear weighted least squares fitting