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Thiolated eggshell membranes sorb and speciate inorganic selenium
Ting Yang1, Ming-Li Chen, Xian-Wei Hu
1Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang 110819, China.
The Analyst
|September 30, 2010
Summary
Eggshell membranes were modified to create thiol-bearing ESMs (TESMs) for selenium speciation. TESMs effectively adsorb and differentiate between Se(IV) and Se(VI) in water samples.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Materials Science
Background:
- Eggshell membranes (ESMs) possess a unique surface rich in disulfide bonds.
- Chemical modification can introduce functional groups, enhancing material properties for adsorption and analysis.
Purpose of the Study:
- To develop a method for selenium speciation using modified eggshell membranes.
- To investigate the adsorption mechanisms of different selenium species on thiol-bearing ESMs.
- To validate the method for analyzing inorganic selenium in environmental and biological samples.
Main Methods:
- Thioglycolate reduction to create thiol groups on ESMs, forming thiol-bearing ESMs (TESMs).
- Characterization of TESMs using scanning electron microscopy and Raman spectroscopy.
- Adsorption and elution experiments for Se(IV) and Se(VI) using a TESM microcolumn.
- Detection and quantification using graphite furnace atomic absorption spectrometry (GFAAS).
Main Results:
- TESMs retain their fibrous network structure after modification.
- TESMs exhibit differential adsorption of Se(IV) (reduced to Se(0)) and Se(VI) (reversibly adsorbed).
- The method achieved an enrichment factor of 17.2, a detection limit of 0.06 μg L(-1), and 3.3% precision for selenium speciation.
- Successful validation using certified reference materials (human hair and rice) and analysis of water samples.
Conclusions:
- Thiol-bearing eggshell membranes provide an effective platform for selenium speciation.
- The developed method allows for the differentiation and quantification of Se(IV) and Se(VI) in complex matrices.
- This approach offers a sensitive and precise technique for environmental selenium monitoring.
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