Protonation of norharmane as a sonochemical dosimeter for organic media: The effect of temperature

The sonolysis of different organic and aqueous media in the presence of norharmane produce its protonation. This simple and reversible reaction is particularly suitable as a dosimetric reaction in order to measure the relative amount of cavitation induced by the ultrasonic irradiation in non aqueous solutions. The protonation rate increases when small amounts of chloroform are added to the solution. The frequency (20 and 475 kHz) and temperature effects on the reaction rate are also studied. Our results show that sonication of aqueous solutions at high frequency leads to a strongly oxidant medium.