An analytical performance of atmospheric pressure glow discharge generated in contact with flowing small size liquid cathode

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

“…Changes in the design of electrolyte solution delivery capillaries made in last several years led to the improvement of the optical thinness of the discharge and its stability [4,[10][11][12][13][16][17][18][19][20][21]. A better reproducibility of the discharge gap results in a much better analytical performance of such modified discharge systems.…”

“…Despite a small size and a compact geometry of the discharge, excitation phenomena occurring in its near-cathode zone result in a simple atomic emission line spectra for a quite large number of metals, less common spectral overlaps of these lines and a relatively low level of the background intensity in their vicinity [1,2,11]. All this makes that dc-APGD generated in contact with the liquid cathode is a very convenient excitation source for the direct analysis of sample solutions by OES on the concentration of different metals present in them at the level of major and minor components or impurities [3][4][5]7,[10][11][12][13].…”

“…The short-term precision, referring to the reproducibility of consecutively measured intensities of atomic emission lines of metals, was commonly poor. Since this figure of merit was closely associated with an inability to reproduce the distance between the metallic anode and the surface of overflowing electrolyte solutions, fluctuations in their flow rate and the size of the cathode surface were critical for the overall performance of these systems [1][2][3][4][5][6][7]. Despite high flow rates used to neglect this inconvenience, any alterations of the discharge gap usually resulted in limits of detection (LODs) for measured metals, i.e., Al, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb and Zn, within the 0.01-1 mg L À 1 range [3].…”

“…From the very beginning, developed low power direct current (dc) APGD, operated between a metallic anode and an electrolyte solution that overflowed an inlet tube or a capillary, was characterized by a very simple design of the discharge cell and low operating costs [1][2][3][4][5][6][7]. Indeed, the electric power used to sustain the discharge is relatively low, i.e., within 20-80 W, and mostly dissipated at the liquid-discharge interface to evaporate water and sputter dissolved metal ions from analyzed solutions [8][9][10][11][12].…”

Generation of solution plasma over a large electrode surface area

“…Plasma in liquids is currently being investigated for application in a variety of fields such as analytical optical emission spectrometry, 10,18,19 nanoparticle synthesis, 3,4,8,15,16 hydrogen production, 20 polymerization, 21,22 and decomposition of dissolved harmful substances. 6,9,[23][24][25] The conventional gas phase plasma has been measured using various diagnostic methods 26,27 including electrical measurement, optical emission spectroscopy (OES) containing broadening of a spectral line, Langmuir probes, and irradiation of laser.…”