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Studies of selectivity in the amaranth method for chlorine dioxide
G L Emmert1, D E Coutant, D L Sweetin
1Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA.
Talanta
|October 31, 2008
Summary
The amaranth method accurately measures chlorine dioxide in water, even with common interfering substances like chlorine. This study details its performance under various conditions.
Area of Science:
- Analytical Chemistry
- Environmental Science
Background:
- Accurate measurement of chlorine dioxide (ClO2) in water is crucial for disinfection efficacy and safety.
- Existing methods may face interference from other water constituents, impacting reliability.
Purpose of the Study:
- To evaluate the amaranth method for quantifying chlorine dioxide in aqueous samples.
- To assess the impact of pH, temperature, and common interfering species on the amaranth method's accuracy.
- To investigate methods for enhancing selectivity of chlorine dioxide detection over free available chlorine.
Main Methods:
- The amaranth method was employed to measure chlorine dioxide.
- Studies examined the effects of varying pH and temperature on method performance.
- Interference studies were conducted using free available chlorine species, chlorite, chlorate, iron (III), oxidized manganese, and monochloramine.
- Gas diffusion-flow injection analysis with an ammonia/ammonium chloride buffer was used to improve selectivity.
Main Results:
- The amaranth method demonstrated reliable performance for chlorine dioxide determination.
- Interference from various common water constituents was quantified.
- Selectivity for chlorine dioxide over free available chlorine was successfully enhanced using specific techniques.
- Method detection limits, accuracy, and precision were established.
Conclusions:
- The amaranth method is a viable technique for measuring chlorine dioxide in water.
- Understanding and mitigating interferences are key to accurate chlorine dioxide analysis.
- Enhanced selectivity protocols improve the reliability of chlorine dioxide measurements in complex matrices.
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