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Biological Samples Preparation for Speciation at Cryogenic Temperature using High-Resolution X-Ray Absorption Spectroscopy
Published on: May 27, 2022
Enzymatic probe sonication as a tool for solid-liquid extraction for total selenium determination by
1REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte da Caparica, Portugal.
Talanta
|March 29, 2008
Summary
A novel enzymatic probe sonication (EPS) method offers a fast and reproducible way to determine total selenium using electrothermal atomic absorption spectrometry (ET-AAS). This approach enhances graphite tube lifespan and provides accurate selenium recovery in various biological samples.
Area of Science:
- Analytical Chemistry
- Environmental Science
- Biochemistry
Background:
- Accurate determination of total selenium is crucial for environmental and biological monitoring.
- Existing methods for selenium determination can be time-consuming or lack reproducibility.
- Enzymatic probe sonication (EPS) offers a potential alternative for sample preparation.
Purpose of the Study:
- To develop and validate a fast and reproducible enzymatic probe sonication (EPS) methodology for total selenium determination.
- To optimize matrix modifiers and enzyme selection for improved accuracy and efficiency.
- To compare the EPS methodology with traditional microwave digestion.
Main Methods:
- Application of enzymatic probe sonication (EPS) for sample preparation.
- Optimization of matrix modifiers: Ni(NO3)2 and Pd(NO3)2 with H2O2.
- Evaluation of different enzymes: protease XIV, substilisin, and trypsin.
- Total selenium determination using electrothermal atomic absorption spectrometry (ET-AAS).
- Validation using BCR-414 plankton and ERM-CE 278 mussel tissue reference materials.
Main Results:
- Palladium nitrate (Pd(NO3)2) combined with hydrogen peroxide (H2O2) as matrix modifiers yielded optimal results.
- Hydrogen peroxide (H2O2) extended graphite tube lifespan by 66% by preventing carbonaceous residue buildup.
- Protease XIV demonstrated critical effectiveness, yielding good selenium recoveries (oyster tissue: 111%; plankton: 106%; mussel tissue: 93%).
- The EPS methodology showed comparable or improved performance to microwave digestion.
Conclusions:
- The developed enzymatic probe sonication (EPS) methodology is a fast, reproducible, and effective approach for total selenium determination.
- The use of Pd(NO3)2 and H2O2 as matrix modifiers significantly improves the ET-AAS analysis and graphite tube longevity.
- Fresh protease XIV is essential for achieving accurate selenium quantification in complex biological matrices.
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