title: Slurry-electrothermal atomic absorption spectrometric determination of aluminium and chromium in vegetables using hydrogen peroxide as a matrix modifier.
abstract: Fast heating programmes for determining aluminium and chromium in vegetables using electrothermal atomic absorption spectrometry with slurry sampling are developed using wall atomization. The build-up of carbonaceous residues inside the atomizer is avoided by adding 4% hydrogen peroxide and 1% nitric acid to the slurries instead of using an air-ashing stage. In accordance with fast-programme methodology, the conventional drying and charring steps are replaced by a modified drying stage. simplifying the heating programmes. For suspensions containing 0.1% m/V of ground vegetables, the relative standard deviation (RSD) is about +/-5% for aluminium. For chromium determination, the use of 0.5-1% m/V suspensions leads to RSDs close to +/-4%. Calibration is carried out using aqueous standards. The aluminium and chromium contents of a number of vegetable samples obtained by using the slurry approach agree with those obtained by means of a conventional procedure based on the total dissolution of the samples. The reliability of the procedures is also confirmed by analysing two certified reference materials.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Murcia, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Viñas
authors.forename: N
authors.initials: N
authors.lastname: Campillo
authors.forename: I
authors.initials: I
authors.lastname: Lopez Garcia
authors.forename: M
authors.initials: M
authors.lastname: Hernandez Cordoba