抄録
In this study we demonstrate formation of nitric oxide in aqueous nitrogen-containing solutions exposed to 50 kHz cavitation-producing ultrasound using electron paramagnetic resonance (EPR) spectroscopy. Formation of ^・NO by ultrasound was independent of the pH of the sonicated water throughout the measured range (pH 3-8.5). The presence of dissolved oxygen was not essential for production of ^・NO: the highest yields of ^・NO (〜 1.2 μM ^・NO/minute) were found under an atmosphere of 40% N_2 and 60% argon. The formation of ^・NO by ultrasound in aqueous solutions can be understood in terms of combustion chemistry- type reactions occurring inside the "hot" collapsing cavitation bubbles. Other N-containing molecules can also serve as a source of nitrogen for ^・NO production.
