title: Simultaneous on-line pre-concentration and determination of trace metals in environmental samples by flow injection combined with inductively coupled plasma mass spectrometry using silica gel modified with niobium(V) oxide.
abstract: This work presents the development of an on-line pre-concentration system for simultaneous determination of Cd, Cu, Ni, V, Zn, Co and Pb in aqueous environmental samples and detection by inductively coupled plasma mass spectrometry. The system is based on cationic retention of the analytes onto a mini-column filled with silica gel modified with niobium(V) oxide. The effects of chemicals and flow variables have been investigated. The optimized operating conditions, selected as a compromise between sensitivity and analytical frequency were: sample pH 7.0, sample flow rate of 6.0mL min(-1), eluent flow rate of 2.0mL min(-1), and eluent (HNO(3)) concentration of 2.5mol L(-1). The relative standard deviation (n=7), enrichment factor and linear working range were 0.8-4.5%, 23.3-37.2 and 0.05-25.0microg L(-1), respectively. Limits of detection were between 0.01 and 0.03microg L(-1). The accuracy of the proposed method was checked with certified materials (NASS-4, NASS-5, CASS-4 and SRM 1643e). Values obtained were in accordance with those reported for the certified materials. Recovery was found to be in the range of 90-110% for a suit of water samples with variable matrices (seawater, tap water and ground water) collected in Florianopolis, Brazil.
authors: Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Brazil.
authors: Heloisa França
authors: HF
authors: Maltez
authors: Mariana Antunes
authors: MA
authors: Vieira
authors: Anderson Schwingel
authors: AS
authors: Ribeiro
authors: Adilson José
authors: AJ
authors: Curtius
authors: Eduardo
authors: E
authors: Carasek
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D017022:Flow Injection Analysis / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D008670:Metals / Q000032:analysis*; D015999:Multivariate Analysis; D009556:Niobium / Q000737:chemistry*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D008670:Metals; D009556:Niobium; D058428:Silica Gel; D012822:Silicon Dioxide