title: 7-amino-4-azaheptyl grafted onto a silica gel as a sorbent for the on-line preconcentration and determination of iron(III) in water samples.
abstract: A new sorbent was synthesized by anchoring 7-amino-4-azaheptyltrimetoxisilane, freshly prepared, to silica gel, producing 7-amino-4-azaheptyl anchored silica gel (AAHSG). This material was characterized by infrared spectroscopy (IR), elemental analysis (CHN), and nitrogen adsorption-desorption isotherms. Isotherms of the adsorption of Fe3+, Fe2+ and Cu2+ on AAHSG were recorded, which indicated that Fe3+ presents a higher affinity by the sorbent. Therefore, AAHSG was successfully employed as a sorbent in a simple flow system for the preconcentration of Fe3+ in natural water samples, such as, river water, lagoonwater, springwater, stream water, well water and two water reference materials (NIST-SRM 1640, NIST-SRM 1643d). The obtained preconcentration factor was 82.2, and the detection limit achieved was 5.9 ng ml(-1). The recovery of spiked water samples ranged from 95.0 - 103.1%.
authors.affiliation: Colégio Militar de Porto Alegre, Av. José Bonifácio, 363, 90040-130, Porto Alegre, RS, Brazil.
authors.forename: Sandra V M
authors.initials: SV
authors.lastname: de Moraes
authors.forename: Mateus M
authors.initials: MM
authors.lastname: Tisott
authors.forename: Caroline D
authors.initials: CD
authors.lastname: Milcharek
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Brasil
authors.forename: Tania M H
authors.initials: TM
authors.lastname: Costa
authors.forename: Márcia R
authors.initials: MR
authors.lastname: Gallas
authors.forename: Edilson V
authors.initials: EV
authors.lastname: Benvenutti
authors.forename: Eder C
authors.initials: EC
authors.lastname: Lima