Sequential injections as an alternative to gradient exploitation for implementing differential kinetic analysis in a flow injection system

Autor(es)

Fortes, Paula R. ^[1] ; Feres, Mario A. ^[1] ; Zagatto, Elias A. G. ^[1] ; Lima, Jose L. F. C. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13400970 Piracicaba - Brazil

^[2] Univ Porto, REQUIMTE, Fac Farm, P-4099030 Oporto - Portugal

• Tipo de documento: Artigo Científico
• Fonte: Talanta; v. 81, n. 4-5, p. 1409-1412, JUN 15 2010.
• Citações Web of Science: 7

Resumo

A novel flow-based strategy for implementing simultaneous determinations of different chemical species reacting with the same reagent(s) at different rates is proposed and applied to the spectrophotometric catalytic determination of iron and vanadium in Fe-V alloys. The method relies on the influence of Fe(II) and V(IV) on the rate of the iodide oxidation by Cr(VI) under acidic conditions, the Jones reducing agent is then needed Three different plugs of the sample are sequentially inserted into an acidic KI reagent carrier stream, and a confluent Cr(VI) solution is added downstream Overlap between the inserted plugs leads to a complex sample zone with several regions of maximal and minimal absorbance values. Measurements performed on these regions reveal the different degrees of reaction development and tend to be more precise Data are treated by multivariate calibration involving the PLS algorithm The proposed system is very simple and rugged Two latent variables carried out ca 95% of the analytical information and the results are in agreement with ICP-OES. (C) 2010 Elsevier B V. All rights reserved. (AU)

• Processo FAPESP: 06/03859-9 - Projeto de sistemas de análises químicas em fluxo envolvendo mecanismos de re-alimentação, aprimoramento das condições de mensuração e/ou calibração multi-variada: aplicação a amostras agro-industriais e ambientais
• Beneficiário: Paula Regina Fortes
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 06/07309-3 - Novas estratégias analíticas para estudos envolvendo biomoléculas
• Beneficiário: Elias Ayres Guidetti Zagatto
• Modalidade de apoio: Auxílio à Pesquisa - Temático