A Novel Highly Sensitive Zeolite-Based Conductometric Microsensor for Ammonium Determination

Abstract

Natural zeolite clinoptilolite was successfully applied in the sensing technology for electrochemical detection of ammonium. A novel ammonium-selective sensor was developed based on clinoptilolite, possessing intrinsic ammonium-sieving and ion exchange capacity. The sensor design allowed measurements in both differential mode and requiring no classical reference electrode. The sensor selectivity towards Na⁺, K⁺, Ca²⁺, Mg²⁺, and Al³⁺ was studied. The limit of detection and the dynamic range of the ammonium-selective conductometric microsensor, determined in the phosphate buffer solution, were 1.0 × 10⁻⁸ M and 0–8 mM, respectively. The ammonium sensor presented high operational and storage stability.

Keywords:

• Ammonium detection
• Clinoptilolite
• Conductometric microsensor
• Ion exchange

Acknowledgments

The authors would like to thank the European Commission for their funding of the Project PIRSES-GA-2008-230802, as well as National Academy of Sciences of Ukraine (complex scientific-technical program “Sensor systems for medical-ecological and industrial purposes”), NATO (Project CBP.NUKR.CLG 984221), and Rhône-Alpes Région for the MIRA project.

Notes

*data are not available.