Comparison of Nitric Oxide Concentrations in μs- and ns-Atmospheric Pressure Plasmas by UV Absorption Spectroscopy

Abstract

In this paper, an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide. The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge (DBD) for applications in plasma medicine. The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen. One of the emitted wavelengths is an important resonance wavelength of nitric oxide (λ = 226.2 nm). By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength, and measuring the change in intensity by the absorbing plasma, the concentration of nitric oxide inside the plasma can be calculated. The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm, so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.

A μs‐Pulsed Dielectric Barrier Discharge Source: Physical Characterization and Biological Effects on Human Skin Fibroblasts

“…Our results revealed NO concentrations between 235 and 265 ppm within the discharge volume. The measurement error of the used method is ±6% . The Association of German Engineers (VDI) Guideline 2310 defined a daily limit of 0.4 ppm (0.5 mg m −3 ) NO to be safe.…”

“…The concentration of nitric oxide was measured directly in the discharge volume. In Peters et al this method and the absorption cross sections used hereby were already described in more detail …”

Decrease of the surface pH of maple and the production of nitrate by three pulsed dielectric barrier discharges

“…As shown in Fig. 7, nitric acid can be formed by various reactions of nitric oxide and nitrogen oxide, which are common species in plasma discharges (Stefanovic et al 2001;Kogelschatz 2003;Peters et al 2016). The process gas is compressed dried air, thus the source for humidity can be the surrounding air and the moisture of the maple samples.…”

Measurement of Exhaled Nitric Oxide in 456 Lung Cancer Patients Using a Ringdown FENO Analyzer

“…The UV region near 226 nm is higher, which corresponds to the electron transition. The absorption cross-section near 226 nm is 1.87 × 10 −18 cm 2 /molecule, four times higher than that of 5.2 µm [46]. This shows that 226 nm can improve the detection sensitivity of NO.…”