Abstract: 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.

Abstract: The apparatus and methods employ momentum separation to implement a particle beam (PB) sampling scheme for the introduction of particulate matter into low pressure (e.g., glow discharge) plasma sources for subsequent atomic emission and mass spectrometry chemical analysis in real time, whether the particles are provided in a continuous stream during the analysis or are collected in situ and analyzed periodically upon obtaining a suitable number of particles to be analyzed. The particulate matter in the particle beam (PB) is subjected to low-power laser scattering to effect particle size analysis. Gases removed by momentum separation are also analyzed.

Abstract: A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance.

Abstract: A method and apparatus for analyzing solid sample materials mounted externally to the apparatus is provided wherein a low pressure glow discharge is initiated by applying a radio frequency potential to an integral, continuous solid sample and an electrically grounded anode in the presence of an inert gas, the glow discharge being maintained such that the inert gas is ionized and the ionized gas sputters sample material, the sputtered sample material then passing into an analyzer region for analysis.

Abstract: A method and apparatus for analyzing solid sample materials is provided wherein a low pressure glow discharge is initiated by applying a radio frequency potential to an integral, continuous sample cathode and an electrically grounded anode in the presence of an inert gas, the glow discharge being maintained such that the inert gas is ionized and the ionized gas sputters sample material, the sputtered sample material then passing into an analyzer region for analysis.

Abstract: Sample material is sputtered from an orifice in a disc mounted in a hollow cathode. A plasma plume is ejected from the orifice and the material sputtered from the smaple is transported directly into the base of the plasma plume. Collisions with particles in the plasma plume excite the sputtered material. Light emission and absorption from the plume are measured and ions in the plume are measured. A chamber surrounding the plasma plume is maintained at about 1 torr. About 15 cc's per minute of argon are supplied to the hollow cathode at 2 torr. The power supply supplies about 200 volts at about 0.10 amps. Low energy argon ions strick the disc at the end of the cathode tube and sputter atoms off the aperture. Atoms collide with particles in the plasma causing excitation, photon emission and ionization of atoms which are measured by optical and mass spectrometers.