Enzymatic probe sonication as a tool for solid–liquid extraction for total selenium determination by electrothermal-atomic absorption spectrometry
2007; Elsevier BV; Volume: 74; Issue: 2 Linguagem: Inglês
10.1016/j.talanta.2007.05.051
ISSN1873-3573
AutoresGonçalo Vale, S Couto Pereira, A.M. Mota, Luís P. Fonseca, José Luís Capelo,
Tópico(s)Trace Elements in Health
ResumoA new fast and reproducible approach is described for the application of the enzymatic probe sonication (EPS) methodology [J.L. Capelo, P. Ximénez-Embún, Y. Madrid-Albarrán, C. Cámara, Anal. Chem. 76 (2004) 233–237] for total selenium determination by electrothermal atomic absorption spectrometry, ET-AAS. Ni(NO3)2 and Pd(NO3)2 were studied as matrix modifiers in conjunction with H2O2, being best results obtained with Pd(NO3)2 plus H2O2. The presence of H2O2 as matrix modifier increases up to 66% the time-life of the graphite tubes, by avoiding the building-up of carbonaceous residues. BCR-414 plankton and ERM-CE 278 mussel tissue reference materials were used for proof-of-the-methodology. Different enzymes, protease XIV, substilisin and trypsin were studied. The use of fresh enzyme was found critical. Good Se recoveries were obtained for oyster tissue, 111%; BCR-414 plankton, 106% and ERM-CE 278 mussel tissue, 93%, when protease XIV was used. Data regarding microwave digestion versus EPS methodology is also presented and discussed.
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