Application of the Potentiometric Stripping Analysis with Constant Current for the Determination of Lithium Ions Using a Spinel-Type Manganese (IV) Oxide-Modified Carbon Paste Electrode

Autor(es)

Teixeira, Marcos F. S. ^[1] ; Bergamini, Marcio F. ^[2] ; Bocchi, Nerilso ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Fac Ciencias & Tecnol, Dept Fis Quim & Biol, BR-19060900 Presidente Prudente, SP - Brazil

^[2] Univ Fed Parana, BR-80060000 Curitiba, Parana - Brazil

^[3] Univ Fed Sao Carlos, Dept Quim, BR-13560 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CURRENT ANALYTICAL CHEMISTRY; v. 6, n. 2, p. 161-165, APR 2010.
• Citações Web of Science: 2

Resumo

A potentiometric stripping method for the measurement of lithium ions at a carbon paste electrode modified with spinel-type manganese oxide is described. The procedure is based on the effective pre-concentration of lithium ions on an electrode surface containing spinel-type MnO(2), with the reduction of Mn(IV) to Mn(III), and the consequent intercalation (insertion) of the lithium ions into the spinel structure. The best current constant stripping analysis (CCSA) response was reached for an electrode composition of 25% (m/m) spinel-type MnO(2) in the paste, 0.1 mol L(-1) TRIS buffer solution at pH 8.0, an accumulation potential of 0.3 V vs. the saturated calomel reference electrode (SCE), a pre-concentration time of 90 s and the application of a small positive constant current (10 A) during the stripping step. The obtained limit of detection was 2.0 x 10(-7) mol L(-1), and the relative standard deviation from five measurements of 2.5 x 10(-6) mol L(-1) lithium ions was 3.8%. (AU)

• Processo FAPESP: 05/01296-4 - Desenvolvimento de metodologia analítica empregando eletrodos modificados com oxo complexos polinucleares de rutênio encapsulado em zeolita
• Beneficiário: Marcos Fernando de Souza Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores