title: On-line preconcentration using a resin functionalized with 3,4-dihydroxybenzoic acid for the determination of trace elements in biological samples by thermospray flame furnace atomic absorption spectrometry.
abstract: In the present paper, an on-line preconcentration procedure for determination of cadmium, copper and zinc by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is proposed. Amberlite XAD-4 functionalized with 3,4-dihydroxybenzoic acid (XAD4-DHB) packed in a minicolumn was used as sorbent material. The metals were retained on the XAD-DHB resin, from which it could be eluted directly to the thermospray flame furnace system. The detection limits were 28 (Cd), 100 (Cu) and 77 ng L(-1) (Zn) for 60s preconcentration time, at a sample flow rate of 7.0 mL min(-1). Enrichment factors were 102, 91 and 62, for cadmium, copper and zinc, respectively. The procedure has been applied successfully to metal determination in biological standard reference materials.
authors.affiliation: Universidade Estadual do Sudoeste da Bahia, Laboratório de Química Analítica, Campus de Jequié, Jequié, Bahia, Brazil. vlemos@uesb.br <vlemos@uesb.br>
authors.forename: Valfredo A
authors.initials: VA
authors.lastname: Lemos
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Bezerra
authors.forename: Fábio A C
authors.initials: FA
authors.lastname: Amorim
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000032:analysis*; D003300:Copper / Q000032:analysis*; D062385:Hydroxybenzoates / Q000737:chemistry*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014131:Trace Elements / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
chemical_list: D062385:Hydroxybenzoates; D014131:Trace Elements; D002104:Cadmium; C009091:protocatechuic acid; D003300:Copper; D015032:Zinc