Chapter 12 - Dielectric barrier discharge devices

Abstract

In this chapter, the use of dielectric barrier discharge (DBD) plasmas for gas phase dissociation of analyte molecules, after vapor generation and prior to spectrometric detection, is discussed. A brief overview of the milestones in DBD history is initially presented, and the first part of the chapter focuses on theoretical background of DBD-driven plasma devices. Basic concepts and physical principles of DBDs are summarized, including discussion on the role of individual plasma species in the plasma ignition and sustaining processes. The most common DBD configurations are introduced and their design compatibility with given spectrometric detectors is outlined. The second part of the chapter is devoted to atomization and excitation of volatile compounds in DBDs. DBD-based atomizers coupled to atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS) detectors are reviewed as well as their atomization/excitation of volatile compounds and optical emission spectrometry (OES) detection. The performance of DBD devices in terms of sensitivity, detection limit, resistance to interferences, etc., is evaluated and compared to atomizers/excitation sources routinely used in AAS, AFS, or OES. Not only the applicability of DBDs to element determination at trace and ultratrace levels is assessed but also their potential for analyte preconcentration and speciation analysis is evaluated. Moreover, an assessment of atomization efficiency and insights into the fate of analyte free atoms in the plasma discharge are provided. Advantages and limitations of DBDs are outlined as well as the expected future trends in their development and applications in the field of vapor generation.