Atmospheric pressure plasmas: A review

During the last two decades atmospheric (or high) pressure non-thermal plasmas in and in contact with liquids have received a lot of attention in view of their considerable environmental and medical applications. The simultaneous generation of intense UV radiation, shock waves and active radicals makes these discharges particularly suitable for decontamination, sterilization and purification purposes. This paper reviews the current status of research on atmospheric pressure non-thermal discharges in and in contact with liquids. The emphasis is on their generation mechanisms and their physical characteristics.

http://iopscience.iop.org/article/10.1088/0022-3727/42/5/053001/pdf

Non-thermal plasmas in and in contact with liquids

Gas discharge plasmas and their applications

Monolithic columns in high-performance liquid chromatography.

Tea polyphenols: prevention of cancer and optimizing health. Discussion 4.

Introduction R.K. Marcus. Fundamental Plasma Processes R.K. Marcus, D. Fang. Atomic Absorption and Flourescence Spectroscopies E.H. Piepmeier. Atomic Emission Spectrometry J.A.C. Broekaert. Glow Discharge Mass Spectrometry W.W. Harrison, F.L. King. Hollow Cathode Discharges S. Caroli, O. Senofonte. Analysis of Nonconducting Sample Types R.K. Marcus, et al. Thin Film Analysis H. Hocquaux. Discharges withing Graphite Furnace Atomizers J.M. Harnly, et al. LaserBased Methods K.R. Hess. Laser-Based Diagnostics of Reactive Plasmas T.A. Miller, B.L. Preppernau. Index.

Glow discharge spectroscopies

Preface. List of Contributors. Introduction (R. K. Marcus and J. A. C. Broekaert). Optical Emission Spectrometry with Glow Discharges (J. A. C. Broekaert). Mass Spectrometry of Glow Discharges (W. W. Harrison, C. Yang and E. Oxley). Radio Frequency Glow Dicharges (R. K. Marcus). Depth Profile Analysis (A. Bengston). Numerical Modeling of Analytical Glow Discharges (A. Bogaerts and R. Gijbels). Application of Glow Discharge Optical Emission Spectrometry in the Steel Industry (K. Kakita). Surfaces, Thin Films and Coatings (R. Payling, et al.). Comparison of Glow Discharge Atomic Spectrometry to Other Surface Analysis Methods (K. Wagatsuma). Analysis of Samples of Nuclear Concern with Glow Discharge Atomic Spectrometry (M. Betti). Analysis of Nonconducting Materials by dc Glow Discharge Spectrometry (A. Bogaerts, et al.). Standards and Reference Materials for Glow Discharge Spectroscopies (M. Winchester). Analysis of Liquid Samples Using Glow Discharge Spectroscopies (R. K. Marcus). GC Speciation with GDMS Detect ion (J. A. Caruso and L. Milstien). Glow Discharge Atomic Emission Spectrometry for the Analysis of Gases and as an Alternative Gas Chromatographic Detector (R. Pereiro, et al.). Low pressure Inductively Coupled Plasmas (H. Evans). Multidimensional Ionization Sources for Plasma source Mass Spectrometry (J. P. Guzowski and G. M. Hieftje). Index.

Glow discharge plasmas in analytical spectroscopy

Radio frequency powered glow discharge atomization/ionization source for solids mass spectrometry

A glow discharge spectroscopy (GDS) source operates at atmospheric pressure. One of the discharge electrodes of the device is formed by an electrolytic solution 27 containing the analyte specimen. The passage of electrical current (either electrons or positive ions) across the solution/gas phase interface causes local heating and the volatilization of the analyte species. Collisions in the discharge region immediately above the surface of the solution results in optical emission and ionization that are characteristic of the analyte elements. As such, these analyte elements can be identified and quantified by optical emission spectroscopy (OES) or mass spectrometry (MS). The device uses the analyte solution as either the cathode or anode. Operating parameters depend on the electrolyte concentration (i.e. solution conductivity) and the gap 35 between the solution surface and the counter electrode. Typical conditions include discharge currents of about 10 to about 60 mA and potentials of about 200 to about 1000 volts. Electrolyte solutions of pH, pNa or pLi values of about 0.5 to about 2 and interelectrode gaps of about 0.5 to about 3 mm produce stable plasmas where the analyte solutions are totally consumed at flow rates of up to about 2.0 mL/min.

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Atmospheric pressure, glow discharge, optical emission source for the direct sampling of liquid media

A liquid sampling–atmospheric pressure glow discharge (LS-APGD) optical emission spectroscopy source is described. This device utilizes an electrolytic solution containing the analyte specimen as one of the discharge electrodes. The passage of an electrical current (either electrons or positive ions) across the solution/gas phase interface causes local heating and the volatilization of the analyte species. Collisions in the negative glow region of the plasma result in optical emission, which is characteristic of the analyte elements. Operation of this device with the analyte solution acting as either the cathode or anode is demonstrated. Typical discharge conditions include currents of 80 mA, potentials of up to 1000 V, with the i-V characteristics exhibiting ‘abnormal’ glow discharge behavior. The analyte-containing electrolyte solution is not limited to hydronium ions, as other salts (e.g.,
Li+ and Na+) also provide sufficient conductivity to sustain the discharge. Spatial maps of analyte emission and spectral background provide insights into the basic operation mechanism of the discharge. The use of a coaxial gas flow around the stainless-steel capillary outlet permits stable plasma operation at low liquid flow rates (0.1–0.3 mL min−1) where pulsation present in the liquid delivery system makes the discharge itself quite unstable. Analytical response curves for Hg, Mg, Na and Pb are demonstrated to have good linearity, with preliminary limits of detection determined to be in the range of 1.1–2.0 ppm (≈10 ng) for 5 µL sample volumes.

/pdf/an-atmospheric-pressure-glow-discharge-optical-emission-4v5i8ywqwr.pdf

R. Kenneth Marcus

Papers

Glow discharge spectroscopies

Glow discharge plasmas in analytical spectroscopy

Radio frequency powered glow discharge atomization/ionization source for solids mass spectrometry

Atmospheric pressure, glow discharge, optical emission source for the direct sampling of liquid media

An atmospheric pressure glow discharge optical emission source for the direct sampling of liquid media