title: Use of polymer-bound Schiff base as a new liquid binding agent of diffusive gradients in thin-films for the measurement of labile Cu²⁺, Cd²⁺ and Pb²⁺.
abstract: A new diffusive gradients in thin-films (DGT) device with solution of polymer-bound Schiff base (Py-PEI) derived from poly(ethyleneimine) and 2-pyridinecarboxaldehyde as the binding agent (Py-PEI DGT) was developed for measuring labile Cu(2+), Cd(2+) and Pb(2+) in waters. In synthetic solution, uptake percentages of Cu(2+), Cd(2+) and Pb(2+) by Py-PEI DGT were 99.2 ± 4.4%, 103.7 ± 4.8% and 98.7 ± 5.5% of the total metals, respectively. Performance of Py-PEI DGT was independent of pH 4-8.5 and ionic strength 1 × 10(-4)-0.1 mol L(-1). The uptake of labile metals showed agreement with the theoretical values of free ions in EDTA solution, and decreased with increase of humic acid (HA) and dissolved organic carbon (DOC) contents in water due to the complexation of HA and DOC with metals. DGT devices containing different liquid binding agents (Py-PEI, polyacrylate (PA) and poly(4-styrenesulfonate) (PSS)) were deployed in the same solution. The higher uptake percentages of Py-PEI DGT (13.2 ± 1.1, 26.5 ± 2.4 and 62.7 ± 3.2% of total Cu(2+), Cd(2+) and Pb(2+)) were obtained with respective to PSS DGT (6.7 ± 0.6, 9.2 ± 0.9 and 29.6 ± 2.7% of total above metals) and PA DGT (8.9 ± 0.9 and 16.2 ± 1.1% of total Cu(2+) and Cd(2+)) due to its relatively strong binding affinity with metals.
authors.affiliation: College of Applied Chemistry, Shenyang University of Chemical Technology, Shenyang 110142, China.
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Fan
authors.forename: Jin-Xiu
authors.initials: JX
authors.lastname: Liu
authors.forename: Dian-Peng
authors.initials: DP
authors.lastname: Sui
authors.forename: Hui
authors.initials: H
authors.lastname: Yao
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
authors.forename: Ting
authors.initials: T
authors.lastname: Sun
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D002681:China; D003300:Copper / Q000737:chemistry*; D004058:Diffusion; D004573:Electrolytes; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007854:Lead / Q000737:chemistry*; D008024:Ligands; D008567:Membranes, Artificial; D008670:Metals / Q000737:chemistry; D019216:Metals, Heavy; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D015203:Reproducibility of Results; D045483:Rivers; D012545:Schiff Bases; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D004573:Electrolytes; D007477:Ions; D008024:Ligands; D008567:Membranes, Artificial; D008670:Metals; D019216:Metals, Heavy; D011108:Polymers; D011725:Pyridines; D012545:Schiff Bases; D014874:Water Pollutants, Chemical; C522921:picolinaldehyde; D002104:Cadmium; D007854:Lead; D003300:Copper; D011094:Polyethyleneimine
keywords: 2-Pyridinecarboxaldehyde; Diffusive gradients in thin-films; Heavy metals; Poly(ethyleneimine); Schiff base