UWSpace is currently experiencing technical difficulties resulting from its recent migration to a new version of its software. These technical issues are not affecting the submission and browse features of the site. UWaterloo community members may continue submitting items to UWSpace. We apologize for the inconvenience, and are actively working to resolve these technical issues.
 

Further Development of Atmospheric Pressure, Self-Igniting Microplasma Devices (MPDs) for Elemental Analysis of Liquid Microsamples Using Atomic Emission Spectrometry (AES)

Thumbnail Image

Files

Weagant_Scott.pdf (2.45 MB)

Date

2011-05-26T17:49:32Z

Authors

Weagant, Scott Richard

Journal Title

Journal ISSN

Volume Title

Publisher

University of Waterloo

Abstract

The present elemental analysis workhorse worldwide is Inductively Coupled Plasma (ICP) Atomic Emission Spectrometry (AES) and Mass Spectrometry (MS). Due to the high power requirements, large gas consumption and the more obvious attribute, size, the ICP is tethered to the lab. Usually, samples must be collected, bottled, sometimes stabilized by acids and then shipped back to the lab for analysis (hours to days to weeks turnover rate). Due to the demand for a portable analyzer this thesis will focus on further development of microplasma devices (MPDs) for portable on-site analysis, in (near) real-time. Mini-In-Torch Vapourization (mini-ITV) is the sample introduction method for MPDs which removes the need for sample preparation (further necessitates portability). Mini-ITV introduces the sample into the MPD via electrothermal vapourization of a dry (water-free) nano- to micro- volume sample. Pneumatic nebulization, the commercially available ICP sample introduction method would extinguish the microplasma. Microplasma stability is the first issue addressed by confining the microplasma to a quartz tube (“wall-stabilized”) in hopes of a more stable MPD background emission. Once stabilized MPD conditions were found key microplasma parameters were studied including MPD power, HVac frequency, operating mode, inter-electrode distance (IED) and observation location, in hopes of improved MPD analytical performance. Microplasma excitation mechanism and maximum energy available in the microplasma for analyte are discussed. Some fundamental characteristics such as excitation temperature (Texc) and changes in atom/ion population with variation in some of the key MPD parameters were also determined.

Description

Keywords

MPD, mini-ITV, On-site analysis, Microplasmas, Elemental analysis

LC Keywords

Citation

URI

http://hdl.handle.net/10012/5985

Collections

Theses
Chemistry