title: Preconcentration and determination of Cu(II) in a fresh water sample using modified silica gel as a solid-phase extraction adsorbent.
abstract: A method was developed to attach 4-amino-2-mercaptopyrimidine (AMP) onto silica gel surface and to determine trace metals. The surface functionalization reaction was performed with a silylant agent, chloropropyltrimethoxysilane (Si-CPTS), and the product, Si-AMP, was characterized by FT-IR and elemental analysis to evaluate the surface modification. The functionalized silica was applied in the sorption of Cu(II) ions from an aqueous medium. The series of adsorption isotherms were adjusted to a modified Langmuir equation and the maximum number of moles of adsorbed copper was 0.447 mmol g(-1). The modified material was placed in a preconcentration system, where it reached an approximately 20-fold enrichment factor using 5mg of Si-AMP. The proposed method was applied in the preconcentration and determination of Cu(II) in a fresh water sample from the Paraná river and was validated through a comparative analysis of a standard reference material (1643e).
authors.affiliation: FEIS-UNESP, Dept. de Física e Química, C.P. 31, 15385-000 Ilha Solteira, SP, Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Pereira
authors.forename: G
authors.initials: G
authors.lastname: Ferreira
authors.forename: L
authors.initials: L
authors.lastname: Caetano
authors.forename: M A U
authors.initials: MA
authors.lastname: Martines
authors.forename: P M
authors.initials: PM
authors.lastname: Padilha
authors.forename: A
authors.initials: A
authors.lastname: Santos
authors.forename: G R
authors.initials: GR
authors.lastname: Castro
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D005782:Gels; D007477:Ions; D007700:Kinetics; D008024:Ligands; D011743:Pyrimidines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013054:Spectrophotometry, Atomic / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: C505203:4-amino-2-mercaptopyrimidine; D005782:Gels; D007477:Ions; D008024:Ligands; D011743:Pyrimidines; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D003300:Copper