title: Cr(III) and Cr(VI) on-line preconcentration and determination with high performance flow flame emission spectrometry in natural samples.
abstract: Methods for the on-line chromatographic preconcentration of Cr(III) and Cr(VI) have been developed. Cr(VI) has been preconcentrated on an RP C18 silica based column with tetrabutylammonium-bromide (TBABr) as ion-pairing agent. Specially for Cr(III) a new and effective preconcentration technique based on the sorption of Cr(III)-ions in a C18 column in presence of KH-phthalate has been developed. The efficiency of sample introduction into the atomic emission spectrometer could be improved by hydraulic high pressure nebulization. For the detection of chromium the acetylene/N(2)O flame has been used as a powerful emission spectrometric source. Applying these steps the detection limit (3sigma) could be improved to 25 pg/mL for Cr(III) and to 20 pg/mL for Cr(VI). The method has been applied for the chromium speciation in natural water samples.
authors.affiliation: Department of Inorganic and Analytical Chemistry, University Kossuth Lajos, PO Box 21, H-4010, Debrecen, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Posta
authors.forename: A
authors.initials: A
authors.lastname: Gáspár
authors.forename: R
authors.initials: R
authors.lastname: Tóth
authors.forename: L
authors.initials: L
authors.lastname: Ombódi