Feasibility of measuring Cr(III) and Cr(VI) in water by laser-induced breakdown spectroscopy using ceramics as the solid support

Autor(es)

Carvalho, Alexandrina A. C. ^[1] ; Silvestre, Daniel M. ^[1] ; Leme, Flavio O. ^[2] ; Naozuka, Juliana ^[3] ; Intima, Danielle P. ^[4] ; Nomura, Cassiana S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Fed ABC, Ctr Ciencias Nat & Humans, Av Estados 5001, BR-09210971 Santo Andre, SP - Brazil

^[3] Univ Fed Sao Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP - Brazil

^[4] Co Saneamento Basico Estado Sao Paulo, BR-02003702 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Microchemical Journal; v. 144, p. 33-38, JAN 2019.
• Citações Web of Science: 5

Resumo

Laser-induced breakdown spectroscopy (LIBS) is a multi-elemental technique with multiple advantages. However, direct determination in liquid samples is not an easy task since laser water interaction can affect the precision and accuracy of the method and cause loss of sensitivity. To enable LIBS application in liquid sample analysis, some strategies such as liquid-to-solid transfer have been used. This work proposes the quantification of chromium in water samples by LIBS using ceramic as the solid support. Results showed that the ceramic selectively adsorbs Cr(III) species at pH 7 and quantification of Cr(VI) species by LIBS was also possible after reduction of this species to Cr(III) using Fe(II) as the reducing agent. Instrumental parameters were optimized, and the best conditions found included a 65 pm spot size, 430 accumulated pulses with 20 mJ pulse(-1), and 0.75 ms of delay time. Calibration was carried out with synthetic calibration standards prepared by adsorption of increasing concentrations of chromium in ceramic. Tap water samples spiked with 0.9 mg L-1 of Cr(III) and 0.1 mg L-1 of Cr(VI) were analysed by the proposed method and recoveries of 105 +/- 2% and 103 +/- 3% were obtained for Cr(III) and Cr(VI), respectively. (AU)

• Processo FAPESP: 13/13478-6 - Avaliação do efeito de propriedades do laser e da amostra na análise direta de carnes por espectrometria de emissão óptica com plasma induzido por laser (LIBS)
• Beneficiário: Flavio de Oliveira Leme
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/11998-0 - Avaliação e produção de material calibrante sintético visando à análise direta de madeiras por LIBS
• Beneficiário: Cassiana Seimi Nomura
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/10346-2 - Desenvolvimento de método de análises quantitativas diretas de materiais silicosos: espectrometria de emissão óptica com plasma induzido por laser e fluorescência de raio-x por reflexão total
• Beneficiário: Cassiana Seimi Nomura
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50951-4 - INCT 2014: Tecnologias Analíticas Avançadas
• Beneficiário: Celio Pasquini
• Modalidade de apoio: Auxílio à Pesquisa - Temático