title: Chromium determination in food by slurry sampling graphite furnace atomic absorption spectrometry using classical and permanent modifiers.
abstract: A simple method, using permanent modifiers, has been developed for chromium (Cr) determination in food of plant origin by the slurry sampling graphite furnace atomic absorption spectrometry. In particular comparison of the action of Mg(NO3)2, iridium (Ir)/niobium (Nb) and iridium (Ir)/tungsten (W) was examined. Finally, for chromium determination in food, the mixture of 2μg of Ir with 10μg of Nb was used as permanent modifier. The analytical procedure was optimised carefully on the basis of the data from pyrolysis and atomisation temperature curves studies. The results obtained for four certified reference materials using external calibration with aqueous standards were in good agreement with the certified values. The precision and accuracy of Cr determination by the described method were also acceptable: the RSD were lower than 10% and recoveries for CRMs were in the range of 95-103%. The characteristic mass for chromium was determined to be 3.9pg and the detection limit for the optimised procedure at the 0.75% (w/v) slurry concentration - 86.6ngg(-1).
authors.affiliation: Maria Curie-Sklodowska University, Faculty of Chemistry, Department of Analytical Chemistry and Instrumental Analysis, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland. Electronic address: rdobrow@poczta.umcs.lublin.pl.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Dobrowolski
authors.affiliation: Maria Curie-Sklodowska University, Faculty of Chemistry, Department of Analytical Chemistry and Instrumental Analysis, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Pawlowska-Kapusta
authors.affiliation: Maria Curie-Sklodowska University, Faculty of Chemistry, Department of Analytical Chemistry and Instrumental Analysis, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Dobrzynska
mesh_terms: D002857:Chromium / Q000737:chemistry*; D005502:Food; D006108:Graphite / Q000737:chemistry*; D013054:Spectrophotometry, Atomic / Q000379:methods*
chemical_list: D002857:Chromium; D006108:Graphite
keywords: Chromium determination; Permanent modifiers; Plant samples; Slurry sampling atomic absorption spectrometry