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Rapid, specific determination of iodine and iodide by combined solid-phase extraction/diffuse reflectance
Matteo P Arena1, Marc D Porter, James S Fritz
1Microanalytical Instrumentation Center, Ames Laboratory-USDOE, and Iowa State University, Ames, Iowa 50011, USA.
Analytical Chemistry
|January 25, 2002
Summary
A new solid-phase extraction method rapidly analyzes trace iodine and iodide in water using membrane disks and diffuse reflectance spectroscopy. This technique offers a quick and efficient way to monitor biocide levels in spacecraft water systems.
Area of Science:
- Analytical Chemistry
- Environmental Science
Background:
- Iodine is crucial for spacecraft water safety as a biocide.
- Accurate and rapid monitoring of iodine and iodide levels is essential.
Purpose of the Study:
- To develop a fast, adaptable trace analysis method for iodine and iodide.
- To validate the method for monitoring ppm levels in spacecraft water.
Main Methods:
- Solid-phase extraction using a polystyrene-divinylbenzene membrane disk impregnated with poly(vinylpyrrolidone) (PVP).
- Concentration of iodine onto the disk, followed by determination using diffuse reflectance spectroscopy (2 s).
- Iodide determination via oxidation to iodine using peroxymonosulfate (Oxone) followed by spectroscopic analysis.
Main Results:
- The method accurately quantifies iodine and iodide in the 0.1-5.0 ppm range.
- Total analysis time is approximately 60 seconds with a relative standard deviation (RSD) of approximately 6%.
- The technique is adaptable for analyzing both iodine and iodide, even in mixed samples.
Conclusions:
- This novel methodology provides a rapid and efficient approach for trace analysis of iodine and iodide.
- The technique is suitable for real-time monitoring applications, such as in spacecraft water systems.
- The diffuse reflectance spectroscopy coupled with solid-phase extraction offers a versatile analytical tool.