Sonochemical species such as nitrite (NO2-) and nitrate (NO3-) were detected in ultrapure aqueous medium with 28 kHz low frequency ultrasound (US) in the range of 200-1200 W output power. The concentration of their anionic ions monitored with a high-performance liquid chromatography increased with increasing US power especially under air atmosphere. When the generation of NO2- and NO3- ions under US exposure was investigated for N2, O2 and Ar-bubbled solutions, no trace of NO2- was observed while NO3- was slightly generated. Under air atmosphere, the concentration of dissolved oxygen in the aqueous medium increased especially when 1200 W power was used. In addition, the bulk pH shifted towards the acidic side with an increase in exposure time, which indicated that NO2- was formed. The formation of oxidizing species under 28 kHz low frequency ultrasonic treatment was confirmed with an absorption spectrum which was dominated by two maxima peaks at 288 nm and 352 nm representing triiodide I3- anion.

中文翻译：

---

超声波化学固定在水性介质中高功率超声作用下生成NO2-和NO3-离子的过程。

在具有200 kHz至1200 W输出功率范围内的28 kHz低频超声（US）的超纯水介质中检测到亚硝酸盐（NO2-）和硝酸盐（NO3-）等声化学物质。高效液相色谱法监测的阴离子离子浓度随美国专利权的增加而增加，尤其是在空气气氛下。当研究在美国暴露下产生的N2，O2和Ar气泡溶液中NO2-和NO3-离子的生成时，未观察到痕量的NO2-，而仅少量生成了NO3-。在空气气氛下，尤其是当使用1200 W功率时，水性介质中溶解氧的浓度增加。另外，随着暴露时间的增加，总pH向酸性侧移动，这表明形成了NO2-。