Microwave-assisted digestion in closed vessels: effect of pressurization with oxygen on digestion process with diluted nitric acid

Autor(es)

Bizzi, Cezar Augusto ^[1] ; de Moraes Flores, Erico Marlon ^[1] ; Picoloto, Rochele Sogari ^[1] ; Barin, Juliano Smanioto ^[2] ; Nobrega, Joaquim Araujo ^{[3, 4]}

Afiliação do(s) autor(es)

^[1] Univ Fed Santa Maria, Dept Quim, Inst Nacl Ciencia & Tecnol Bioanalit, BR-97105900 Campinas, SP - Brazil

^[2] Univ Fed Santa Maria, Dept Tecnol & Ciencia Alimentos, BR-97105900 Campinas, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos, SP - Brazil

^[4] Inst Nacl Ciencias & Tecnol Analit Avancadas, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANALYTICAL METHODS; v. 2, n. 6, p. 734-738, JUN 2010.
• Citações Web of Science: 43

Resumo

The efficiency of diluted nitric acid solutions under oxygen pressure for decomposition of bovine liver was evaluated using microwave-assisted wet digestion Calcium, Cu, Fe. Mg, Mn and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP OES). Efficiency was evaluated by determining the residual carbon content (RCC) by ICP OES and residual acidity in digests Samples (up to 500 mg) were digested using nitric acid solutions (0 1, 0 5, 1, 2, 3, 7, and 14 mol L(-1) HNO(3)) and the effect of oxygen pressure was evaluated using pressures of 0.5, 1, 1 5 and 2 MPa It was demonstrated that 2 and 0 5 mol L(-1) nitric acid solutions may be used for efficient digestion of 500 and 100 mg of bovine liver, respectively, with oxygen pressures ranging from 0 5 to 2 MPa Using these conditions, less than 0 86 and 021 mL of concentrated nitric acid were necessary to digest 500 and 100 mg of sample, respectively. Similar digestion efficiencies for both conditions were obtained under pressures of O(2) ranging from 0 5 to 2 MPa. The residual acidities in final digests were lower than 24% when compared to the initial amount of acid used for digestion The accuracy of the proposed procedure was evaluated using certified reference materials of bovine liver and bovine muscle Using a solution of 2 mol L(-1) with oxygen pressure of 0.5 MPa for 500 me of sample. the agreement with certified values ranged from 96 to 105% (n = 5). Using the proposed procedure with diluted nitric acid it was possible to obtain RCC values lower than 15% that is important for minimizing the generation of laboratory residues and improving limits of detection (AU)

• Processo FAPESP: 08/57808-1 - Instituto Nacional de Ciências e Tecnologias Analíticas Avançadas - INCTAA
• Beneficiário: Celio Pasquini
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 06/59083-9 - Espectrometria de massa acoplada ao plasma induzido: aspectos fundamentais e aplicações
• Beneficiário: Joaquim de Araújo Nóbrega
• Modalidade de apoio: Auxílio à Pesquisa - Temático