title: Simultaneous spectrophotometric determination of trace copper, nickel, and cobalt ions in water samples using solid phase extraction coupled with partial least squares approaches.
abstract: A simultaneous spectrophotometric determination method for trace heavy metal ions based on solid-phase extraction coupled with partial least squares approaches was developed. In the proposed method, trace metal ions in aqueous samples were adsorbed by cation exchange fibers and desorbed by acidic solution from the fibers. After the ion preconcentration process, the enriched solution was detected by ultraviolet and visible spectrophotometer (UV-Vis). Then, the concentration of heavy metal ions were quantified by analyzing ultraviolet and visible spectrum with the help of partial least squares (PLS) approaches. Under the optimal conditions of operation time, flow rate and detection parameters, the overlapped absorption peaks of mixed ions were obtained. The experimental data showed that the concentration, which can be calculated through chemometrics method, of each metal ion increased significantly. The heavy metal ions can be enriched more than 80-fold. The limits of detection (LOD) for the target analytes of copper ions (Cu2+), cobalt ions (Co2+) and nickel ions (Ni2+) mixture was 0.10μgL-1, 0.15μgL-1and 0.13μgL-1, respectively. The relative standard deviations (RSD) were less than 5%. The performance of the solid-phase extraction can enrich the ions efficiently and the combined method of spectrophotometric detection and PLS can evaluate the ions concentration accurately. The work proposed here is an interesting and promising attempt for the trace ions determination in water samples and will have much more applied field.
authors.affiliation: State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China. Electronic address: guoyugao@tjpu.edu.cn.
authors.forename: Yugao
authors.initials: Y
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: He
authors.initials: H
authors.lastname: Zhao
authors.affiliation: School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: Yelin
authors.initials: Y
authors.lastname: Han
authors.affiliation: School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: Qingyin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China.
authors.forename: Xihui
authors.initials: X
authors.lastname: Bian
keywords: Cation exchange fiber; Heavy metal ions; Partial least squares; Solid phase extraction; Ultraviolet and visible spectrophotometer