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Effect of interfering ions on hexamethyldisiloxane microdiffusion method
R W Kahama1, D N Kariuki, L W Njenga
1Department of Chemistry, PO Box 30197, University of Nairobi, Nairobi, Kenya.
Talanta
|October 31, 2008
Summary
Hexamethyldisiloxane (HMDS) addition to acid diffusion ensures complete ionic fluoride recovery, even with high aluminum concentrations. This method improves fluoride analysis in challenging samples like soil and plants.
Area of Science:
- Analytical Chemistry
- Environmental Science
Background:
- Aluminum ions interfere with accurate fluoride determination.
- Traditional acid diffusion methods struggle with high aluminum concentrations.
Purpose of the Study:
- To develop a method for complete ionic fluoride recovery in the presence of aluminum.
- To analyze fluoride in complex environmental samples like soil and plants.
Main Methods:
- Acid diffusion with hexamethyldisiloxane (HMDS) for fluoride isolation.
- Direct determination of fluoride using a combination fluoride electrode.
- Atomic Absorption Spectrophotometry (AAS) for aluminum, iron, and silicon analysis.
Main Results:
- Complete fluoride recovery was achieved with HMDS, even with high aluminum levels.
- Fluoride recovery decreased significantly without HMDS as aluminum concentration increased.
- The method was successfully applied to soil and plant samples.
Conclusions:
- HMDS-assisted acid diffusion is a robust technique for accurate fluoride analysis in the presence of aluminum.
- This method enhances the reliability of fluoride measurements in environmental matrices.
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