In Search for an Ionic Liquid with the Best Performance during ²¹⁰Pb/²¹⁰Bi Cherenkov Counting in Waters on an LS...

Area of Science:

• Radiochemistry
• Analytical Chemistry
• Materials Science

Background:

• Lead-210 (Pb) and Bismuth-210 (Bi) are important environmental radioisotopes.
• Accurate detection of low-level Pb in aqueous samples is challenging.
• Ionic liquids (ILs) are being explored for their potential to enhance Cherenkov radiation detection.

Purpose of the Study:

• To evaluate the performance of novel ionic liquids for 210Pb/210Bi detection in water.
• To investigate the wavelength-shifting properties of ILs for Cherenkov counting.
• To determine if ILs can improve detection limits for 210Pb quantification.

Main Methods:

• Experiments were conducted using a Quantulus 1220 liquid scintillation spectrometer.
• Cherenkov counting was employed with and without the addition of various ionic liquids.
• Molecular simulations were performed to understand the structural basis of wavelength-shifting behavior.

Main Results:

• 1-butyl-3-methylimidazolium salicylate demonstrated superior performance compared to 2-hydroxypropylammonium salicylate.
• Other benzoate-based ionic liquids with the same cation did not exhibit wavelength-shifting effects.
• Only ionic liquids containing the salicylate anion showed a significant wavelength-shifting effect.

Conclusions:

• Ionic liquids, particularly those with salicylate anions, can enhance Cherenkov counting efficiency for 210Pb/210Bi detection.
• The use of these ILs can lead to lower detection limits for 210Pb in water samples.
• Understanding IL structure is key to optimizing their application as wavelength shifters in scintillation counting.