Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1265782 | Ultrasonics Sonochemistry | 2016 | 10 Pages |
Abstract
When ultrasound (US) was exposed to aqueous coumarin solution in air atmosphere, the UV-visible and fluorescence spectra of the probe were measured at different US exposure times. The US exposure was carried out at 43Â kHz and 500Â kHz with different out-put power. It was found that the 500Â kHz US produced umbelliferone fluorescence, while the 43Â kHz US had no fluorescence. In addition, the coumarin absorbance at 270Â nm maximum was decreased with in cases of the US exposure time. In contrary, the fluorescent intensity of umbelliferone at 460Â nm increased with increasing of US exposure time. This exhibited that the coumarin probe was converted to umbelliferone by the US exposure, when the 500Â kHz US was operated. This was facted that the coumarin framework was caused with addition of OH groups which was generated by the 500Â kHz US. Therefore, the umbelliferone fluorescent became a probe to estimate OH radical in US medium. Furthermore, the chemo-fluorometry showed that the emission maximum of the formed umbelliferone could probe the bulk pHs in the US aqueous medium.
Related Topics
Physical Sciences and Engineering
Chemistry
Chemistry (General)
Authors
Kohsuke Hirano, Takaomi Kobayashi,