| Ultrasonic chemistry involves the use of ultrasound irradiation for the purpose of accelerating chemical reaction rate, and is playing a more and more important role now in the fields such as extraction, synthesis, analytical chemistry and waste water treatment. In this thesis, two researches have been performed:(1) Fe3O4 MNPs were recently reported to exhibit intrinsic enzyme mimetic activity similar to natural peroxidases. In the presence of ultrasound irradiation and H2O2, Fe3O4 MNPs were applied to the treatment of Rhodmanine B (RhB) based on this novel properties. Conditions such as RhB concentration, H2O2 concentration, pH value and Fe3O4 dosage were investigated. Further experiments indicated that superoxide anion was the main decomposition product of H2O2. What's more, both Fe(â…¢) and Fe(â…¡) proved to play important roles in the catalytic behavior of Fe3O4 MNPs.(2) Cyanuric acid is attracting more attention due to its potential toxicity. In the present work, an ultrasonic extraction method in combination with high-performance liquid chromatography (HPLC) was proposed for the determination of cyanuric acid in pet food. Among different solvents, methanol was found to be the best one as the extractant due to the strong polarity of cyanuric acid and the interferences in the pet food. The ultrasonic energy permitted an extraction time as less as 30 min, which was much shorter than 240 min required in the magnetic stirring extraction. Under the selected HPLC conditions, the HPLC method could respond linearly with cyanuric acid at concentrations from 0.008 to 4.0 mg L-1 with a detection limit of 0.002 mg L-1. In the analysis of practical spiked pet food samples, the new method yielded satisfactory results.
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