Sonoluminescent spectroscopy with sonoluminescence initiation by ultrahigh-frequency ultrasound: detecting the content of the main substance in highly saturated solutions

This paper presents further development of sonoluminescence spectroscopy, a novel method of chemical analysis. In particular, the application of ultrahigh-frequency (10.0 MHz) ultrasound for the initiation of sonoluminescence was considered for detecting the content of the main substance in natural brines and highly concentrated technological solutions. The influence of the initiating ultrasound frequency on the intensity of sonoluminescence of CsCl, LiCl, and NaCl was established. The identity of the processes of cavitation bubble formation and collapse in solutions of alkali metal chlorides was demonstrated. It was shown that the maximum intensity of sonoluminescence for alkali metal chlorides is reached at an ultrasound frequency of 20–22 MHz. A technique has been developed for determining the content of Cs, Li, and Na in highly concentrated technological solutions and brines using ultrahigh-frequency ultrasound to initiate sonoluminescence. The validity of the method was verified by analyzing the same samples with alternative methods: gravimetry and sonoluminescence spectroscopy using both high- and low-frequency ultrasound for sonoluminescence initiation.