The effect of a miniature argon flow rate on the spectral characteristics of a direct current atmospheric pressure glow micro-discharge between an argon microjet and a small sized flowing liquid cathode

Direct Current Atmospheric Pressure Microdischarge Generated between a Miniature Flow Helium Microjet and a Flowing Liquid Cathode

“…On the other hand, it can also be assumed that the increasing flow rate of He in the microjet caused an increase in the concentration of He atoms in the near liquid cathode zone. Considering the nature of APGDs generated in contact with liquids, it was reasonably that the main source of OH, H, and O radicals in the observed discharge region was the H 2 O vapour and/or H 2 O + (H 3 O + ) ions resulted from the sputtering of the liquid cathode solution . Hence, it can be expected that atoms of He in these conditions had a little influence on the production rate of these species.…”

“…The rotational temperature of N 2 was estimated from the profile of the N 2 (0–2) band in the range of 376–380 nm. Two the most prominent H lines, i.e., H α at 656.28 nm and H β at 486.13 nm, were employed for the calculation of the excitation temperature ( T exc ) using a two‐line radiation ratio method . The uncertainty of measurements of average optical temperatures was typically within 3–10% ( T rot , T vib ) and 3–7% ( T exc ).…”

“…In another work, Nikiforov et al determined the concentration of OH radicals in the gas phase of the Ar or He microdischarge using laser induced fluorescence (LIF). The spectroscopic diagnostic of atmospheric pressure glow microdischarge (µAPGD) generated between an Ar microjet anode and a miniaturized flowing liquid cathode was performed by Jamroz et al as a function of the miniature Ar flow rate up to 300 sccm. The excitation temperature of Ar atoms and rotational temperatures determined from OH and N 2 molecular spectra in the near liquid phase region were changed in the range of 7400–7800 K, 2000–2600 K, and 1600–1950 K, respectively, pointing the non‐equilibrium state of the microdischarge.…”

The improvement of the analytical performance of direct current atmospheric pressure glow discharge generated in contact with the small-sized liquid cathode after the addition of non-ionic surfactants to electrolyte solutions

“…Additionally, reasonably good precision and the accuracy similar to this obtained with FAAS/FAES are obtained in the analysis of complex environmental samples demonstrating the same the reliability of such modified discharge system and measurements made. It could be expected that changes in the composition of the electrolyte solution of the liquid cathode [12,22,33] or the replacement of a solid anode with a miniature gas flow through a nozzle electrode [12,29,34] would be beneficial for the performance of the dc-APGD excitation source and contribute to the extension of its applications in analytical atomic spectrometry.…”

“…In consequence, the concentration of positive ions of studied metals available for recombination processes in the near-cathode zone of the discharge is increased while the concentration of the water vapor in the core of the discharge is rather decreased. A lower contribution of the water vapor in the phase of the discharge seemingly leads to an increase in the energy and/or the number of free electrons responsible for recombination and excitation processes [1,[27][28][29][30]. Certainly, a combination of both phenomena would directly influence the analytical performance of the examined discharge system.…”