title: Synthesis, characterization and application of a novel mercapto- and amine-bifunctionalized silica for speciation/sorption of inorganic arsenic prior to inductively coupled plasma mass spectrometric determination.
abstract: A bifunctional sorbent, (NH(2)+SH)silica, containing both amine and mercapto functionalities was prepared by modification of silica gel with 3-(triethoxysilyl)propylamine and (3-mercaptopropyl)trimethoxysilane. In addition to the bifunctional sorbent, silica gel was modified individually with the functional mercapto- and amino-silanes, and the mono-functional sorbents, namely (SH)silica and (NH(2))silica, were also mechanically mixed ((NH(2))silica+(SH)silica) for the sake of comparison of sorption performances. It has been demonstrated that (SH)silica shows quantitative sorption only to As(III) at two pH values, 1.0 and 9.0, while (NH(2))silica displays selectivity only towards As(V) at pH 3.0. On the other hand, the bifunctional (NH(2)+SH)silica possesses the efficient features of the two mono-functionalized sorbents; for example, it retains As(III) at a wider pH range, from 1.0 to at least 9.0 with the exception at pH 2.0, and it also shows quantitative sorption to As(V) at pH 3.0. This property gives the bifunctional (NH(2)+SH)silica a better flexibility in terms of sorption performance as a function of solution pH. The mechanically mixed (NH(2))silica+(SH)silica exhibits a similar but less efficient sorption behavior compared to the bifunctional sorbent. Desorption of both As(III) and As(V) species can be realized using 0.5M NaOH. The validity of the proposed method was checked through the analysis of a standard reference material and a good correlation was obtained between the certified (26.67 μg L(-1)) and determined (27.53±0.37 μg L(-1)) values. Spike recovery tests realized with ultrapure water (93.0±2.3%) and drinking water (86.9±1.2%) also confirmed the applicability of the method.
authors.affiliation: Department of Chemistry, İzmir Institute of Technology, Urla, İzmir, Turkey.
authors.forename: Ezel
authors.initials: E
authors.lastname: Boyacı
authors.forename: Ali
authors.initials: A
authors.lastname: Cağır
authors.forename: Talal
authors.initials: T
authors.lastname: Shahwan
authors.forename: Ahmet E
authors.initials: AE
authors.lastname: Eroğlu
mesh_terms: D000327:Adsorption; D000588:Amines / Q000737:chemistry; D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods*; D017646:Organosilicon Compounds; D011437:Propylamines / Q000737:chemistry; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D000588:Amines; D060766:Drinking Water; D017646:Organosilicon Compounds; D011437:Propylamines; D012821:Silanes; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; C102833:(3-mercaptopropyl)trimethoxysilane; D001151:Arsenic