Over the last 15 years there has been a great deal of interest in the potential development of spectrochemical sources that come with lower operational overhead than the inductively-coupled plasma (ICP). There are many driving forces for the development of such devices, even with the likely sacrifices in terms of analytical performance. Some of these devices operate in ambient atmospheres in the electrical regime of glow discharge (GD) plasmas, wherein one of the electrodes is an electrolytic solution that serves as the medium for sample introduction. The basic operational space and analytical performance of these devices has been reviewed in the recent past. We focus in this review on the design and operational attributes of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma. The rationale for the development and basic source designs are first considered, followed by practical contrasts to the other devices provided. A number of studies have been performed to assess the fundamental plasma characteristics including kinetic and excitation temperatures, as well as charged particle densities. Perhaps the greatest difference between the LS-APGD and the other plasmas is the analytical versatility that has been demonstrated. Analytes can be determined by optical emission spectroscopy or mass spectrometry (OES/MS), with sampling regimes consisting of solution phase introduction, particles produced via laser ablation, or through an ambient desorption mechanism directly from the solid state. Finally, the microplasma can be operated in alternative modes wherein either elemental or molecular-form mass spectra are obtained. It is believed that the simplicity of the LS-APGD design, combined with its analytical versatility, suggest that this singular platform could be implemented to address diverse analytical challenges.

A portable handheld laser-induced breakdown spectroscopy (HH LIBS) instrument was evaluated as a rapid method to qualitatively analyze rare earth elements in a uranium oxide matrix. This research is motivated by the need for development of a method to perform rapid, at-line chemical analysis in a nuclear facility, particularly to provide a rapid first pass analysis to determine if additional actions or measurements are warranted. This will result in the minimization of handling and transport of radiological and nuclear material and subsequent exposure to their associated hazards. In this work, rare earth elements (Eu, Nd, and Yb) were quantitatively spiked into a uranium oxide powder and analyzed by the HH LIBS instrumentation. This method demonstrates the ability to rapidly identify elemental constituents in sub-percent levels in a uranium matrix. Preliminary limits of detection (LODs) were determined with values on the order of hundredths of a percent. Validity of this methodology was explored by employing a National Institute of Standards and Technology (NIST) standard reference materials (SRM) 610 and 612 (Trace Elements in Glass). It was determined that the HH LIBS method was able to clearly discern the rare earths elements of interest in the glass or uranium matrices.