Investigation of an alternating current plasma as an element selective atomic emission detector for high-resolution capillary gas chromatography and as a source for atomic absorption and atomic emission spectrometry

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7165270

Ombaba, J M

This thesis deals with the construction and evaluation of an alternating current plasma (ACP) as an element-selective detector for high resolution capillary gas chromatography (GC) and as an excitation source for atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). The plasma, constrained in a quartz discharge tube at atmospheric pressure, is generated between two copper electrodes and utilizes helium as the plasma supporting gas. The alternating current plasma power source consists of a step-up transformer with a secondary output voltage of 14,000 V at a current of 23 mA. The chromatographic applications studied included the following: (1) the separation and selective detection of the organotin species, tributyltin chloride (TBT) and tetrabutyltin (TEBT), in environmental matrices including mussels (mytilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienylmanganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer was utilized as a sample introduction device for aqueous solutions when the ACP was employed as an atomization source for atomic absorption spectrometry and as an excitation source for atomic emission spectrometry. Plasma diagnostic parameters studied include spatial electron number density across the discharge tube, electronic, excitation and ionization temperatures. Interference studies both in absorption and emission modes were considered. The evaluation of a computer-aided optimization program, Drylab GC, using spearmint oil and Environmental Protection Agency (EPA) standard mixture as probes is discussed. The program is used for separation optimization and prediction of gas chromatographic parameters. The program produces a relative resolution map (RRM) which guides the analyst in selecting the most favorable temperature programming rate for the separation.

• Research Organization: Massachusetts Univ., Lowell, MA (United States)
• OSTI ID: 7165270
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
EXCITATION SYSTEMS
EMISSION SPECTROSCOPY
PLASMA PRODUCTION
FUEL ADDITIVES
GAS CHROMATOGRAPHY
TIN COMPOUNDS
ALTERNATING CURRENT
ORGANOMETALLIC COMPOUNDS
PLASMA DIAGNOSTICS
ADDITIVES
CHROMATOGRAPHY
CURRENTS
ELECTRIC CURRENTS
ORGANIC COMPOUNDS
SEPARATION PROCESSES
SPECTROSCOPY
400102* - Chemical & Spectral Procedures
400201 - Chemical & Physicochemical Properties