title: PVDF-ErGO-GRC electrode: A single setup electrochemical system for separation, pre-concentration and detection of lead ions in complex aqueous samples.
abstract: An effective electrode was developed based on electromembrane extraction (EME) and square wave voltammetry (SWV) for simultaneous separation, pre-concentration and determination of lead (II) (Pb(II)) ions in complex aqueous samples. Electrochemically reduced graphene oxide-graphite reinforced carbon (ErGO-GRC) was utilized in conjunction with the SWV. Pb(II) ions were extracted from an aqueous sample solution into an acidic acceptor phase (1M HCl) in the lumen of the polyvinylidene fluoride (PVDF) membrane bag by the application of voltage of maximum 6 V across the supported liquid membrane (SLM), consisting of organic solvent and di-(2-ethylhexyl)phosphoric acid (D2EHPA). The parameters affecting the EME were optimized for Pb(II) ions. The optimum EME conditions were found to be 20% D2EHPA in 1-octanol impregnated in the wall of PVDF membrane (PVDF17) as the SLM, extraction time of 20 min, pH of sample solution of 8 and a voltage of 5 V. The PVDF-ErGO-GRC electrode system attained enrichment factors of 40 times and 80% of extraction with relative standard deviations (n=5) of 8.3%. Good linearity ranging from 0.25 to 2 nM with coefficients correlation of 0.999 was obtained. The Pb(II) ions detection limit of PVDF-ErGO-GRC electrode was found to be 0.09 nM. The newly developed single setup electrochemical system was applied to complex aqueous samples such as tap, river and sea water to evaluate the feasibility of the method for applications.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM , 81310 Skudai, Johor, Malaysia.
authors.forename: Kunashegaran
authors.initials: K
authors.lastname: Hamsawahini
authors.affiliation: Centre for Environmental Sustainability and Water Security (IPASA), Research Institute for Sustainable Environment (RISE), Universiti Teknologi Malaysia, UTM, 81310 Skudai, Johor, Malaysia. Electronic address: salemsathishkumar@gmail.com.
authors.forename: Palanivel
authors.initials: P
authors.lastname: Sathishkumar
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM , 81310 Skudai, Johor, Malaysia; UTM Palm Oil Research Center, Research Institute for Sustainable Environment (RISE), Universiti Teknologi Malaysia, UTM, 81310 Skudai, Johor, Malaysia. Electronic address: rahmalan@utm.my.
authors.forename: Rahmalan
authors.initials: R
authors.lastname: Ahamad
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM , 81310 Skudai, Johor, Malaysia; Centre for Environmental Sustainability and Water Security (IPASA), Research Institute for Sustainable Environment (RISE), Universiti Teknologi Malaysia, UTM, 81310 Skudai, Johor, Malaysia.
authors.forename: Abdull Rahim Mohd
authors.initials: AR
authors.lastname: Yusoff
mesh_terms: D055664:Electrochemical Techniques / Q000379:methods* / Q000592:standards; D006108:Graphite / Q000737:chemistry*; D017736:Ion-Selective Electrodes / Q000592:standards; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D011145:Polyvinyls / Q000737:chemistry*; D014867:Water / Q000032:analysis*; D005465:Fluorocarbon Polymers
chemical_list: D006108:Graphite; D007854:Lead; D011145:Polyvinyls; D014867:Water; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers
keywords: Electromembrane extraction; Graphene oxide; Graphite reinforced carbon; Lead ions; Polyvinylidene fluoride; Square wave voltammetry