Abstract
Sonochemical effects in liquids and solutions irradiated by sound wave with high intensity are influenced by many factors: the ultrasound frequency and intensity, the shape of the reaction cell, the sample volume, the experimental temperature, etc. Therefore, it is difficult to compare the reported results carried out by the different laboratories. Calorimetry or chemical dosimetry is sometimes used to measure the ultrasonic power or intensity in a reaction vessel. However, standardization of ultrasonic power for sonochemistry is desired. Last year, Japan Society of Sonochemistry has organized a working group for standardization of ultrasonic power for sonochemistry. In four laboratories, the following methods were examined in the frequency range from 20kHz to 1.2MHz with different apparatus: 1) Calorimetry, 2) Measurement of absorbance of Fe^<3+> produced in Fricke solution, 3) Measurement of absorbance of I_3^- generated in 0.1M KI solution, 4) Measurement of decomposition ratio of porphyrin in solution. There is good correlation between absorbance of Fe^<3+> and that of I_3^- reported by different laboratories. We recommend the method (3) for standardization of ultrasonic power for sonochemistry. We will also discuss the frequency dependence of the sonochemical effect on basis of the results obtained from four methods.
