This paper reviews the most common methods of generation of plasmas using microwaves with special emphasis on recently developed microwave plasma (MWP) sources for analytical applications. The art and science of microwave plasma optical and mass spectroscopy instrumentation (MWP-OES/MS), and the applications are briefly presented, including very recent advances in the field as of 2012. The design and operation of MWPs is discussed to provide a basic understanding of the most important selection criteria when designing MWP systems. The various plasma generation systems described include single-electrode capacitive microwave plasmas, electrodeless inductively coupled plasmas, multi-electrode systems energized with stationary or rotating fields. We also discuss various technical realizations of MWP sources for selected applications. Examples of technical realizations of plasmas in closed structures (cavities), in open structures (surfatrons, planar plasma sources), and in magnetic fields (Hammer cavity) are discussed in detail. Finally, we mention micro- and mini-discharges as convenient sources for miniaturized spectrometric systems. Specific topics include fundamental aspects of MWP, i.e., recent advances in the construction of analytical MWPs (coaxially coupled cavities, strip-line technology, multi-point energizing, power combining, rotating field-excited plasmas), operational characteristics, analytical characteristics and applications. Special reference is made to coupling with OES for determination of chromatographic effluents and particle sizing. The developments in elemental and molecular MS applications in both low-power and high-power MWPs are also discussed.

The construction of plasma reactors and the technological process of obtaining water rich in hydrogen and characterized by a negative oxidation potential are presented in the publication. Hydrogen-rich water was obtained based on non-plasma technology and water saturation with hydrogen gas in a reactor vessel or in glass bottles. We have developed a plasma flow reactor that allows for contactless microstructuring and modifying the properties of water / aqueous solutions by resonant stochastic vibration amplification of selected chemical compounds in water with broadband electromagnetic noise with frequencies ranging from 100 Hz to 50 MHz generated during plasma discharge. This water is then saturated with hydrogen gas in the reactor or in glass bottles. The water obtained in the reactor is characterized by a high concentration of hydrogen (8 mg/L) and a negative oxidation-reduction potential (ORP) value (-450 mV). In this technology, the process of saturating water with hydrogen in a 1 m³ tank at a temperature of 20^oC takes about 30 minutes. In the technology of obtaining water with negative ORP potential in the bottles, the process of saturating the water with hydrogen lasts only 5-10 seconds. Water obtained with such technology in the glass bottles does not contain much hydrogen gas after 24 hours, while it is characterized by a negative ORP value of about -380 mV even for a period of three months. Obtaining water with presented parameters is possible only in the case of water subjected to the influence of broadband electromagnetic noise with frequencies ranging from 100 Hz to 50 MHz generated during plasma discharge.

A fast and green approach for the non-chromatographic assaying of volatile metalorganic compounds (VMOCs) is presented, involving the use of thermal desorption microwave-induced plasma optical emission spectrometry for the multi-species simultaneous determination of VMOCs in wastewater plant samples after headspace solid-phase microextraction (HSSPME-TD-MIP-OES), and optimized as a tool for the assessment of ambient exposure to hazardous VMOC pollutants. With the aim of VMOC monitoring, all species are separated and quantified within 10 s in comparison with about 10–20 min required by conventional GC-based procedures. Calibration against aqueous standards was carried out for several metalorganic species. The method was successfully applied for the quantitative extraction of As, Bi, Hg, Sb, Si and Sn compounds. Limits of detection ranging from 5 to 30 ng L⁻¹ and relative standard deviations lower than 4% were obtained. The method is appropriate for high-sample-throughput measurements, and it proved to be suitable for the analysis of wastewater and sewage sludge samples.