Organotin compounds: an ionophore system for fluoride ion recognition

Area of Science:

• Electroanalytical Chemistry
• Materials Science

Background:

• Developing ion-selective electrodes (ISEs) is crucial for accurate anion detection.
• Organotin compounds offer potential as ionophores in ISE membranes.
• Fluoride detection remains a significant analytical challenge due to interference.

Purpose of the Study:

• To synthesize and characterize novel organotin compounds for use as ionophores in fluoride-selective membrane electrodes.
• To optimize membrane formulations for enhanced selectivity and sensitivity towards fluoride ions.
• To evaluate the performance of the developed electrodes for direct fluoride determination in real-world samples.

Main Methods:

• Synthesis of organotin compounds: (L(CN)RSnF2)n and (L(CN)SnF3)n.
• Fabrication of membrane electrodes incorporating organotin ionophores and sodium tetraphenylborate.
• Potentiometric measurements to assess selectivity, detection limit, and response slope.
• UV-Vis spectroscopy to investigate the response mechanism.

Main Results:

• Organotin compounds I-III demonstrated effective ionophore activity for fluoride.
• Optimized electrodes showed high selectivity for fluoride over a range of common anions.
• The best-performing electrode exhibited a detection limit of 7.9 x 10(-7) M and a slope of 62.7 mV/decade.
• The electrode successfully determined fluoride in drinking mineral water samples.

Conclusions:

• Novel organotin compounds are effective ionophores for creating highly selective fluoride-sensing electrodes.
• The developed membrane electrode offers excellent potentiometric performance and low detection limits for fluoride.
• The electrode is suitable for direct and reliable fluoride determination in complex matrices like drinking water.