Award Date

1-1-1996

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Committee Member

Klaus J. Stetzenbach

Number of Pages

83

Abstract

A method was developed for the separation and identification of difluorobenzoic acids by high performance liquid chromatography/mass spectrometry (HPLC/MS) with a particle beam interface (PB). The development of this method included the optimization of the mobile phase and MS parameters for the best separation and detection of the analytes. A performance evaluation procedure for PB HPLC/MS operation was established. Ionization control and ion pairing techniques were employed in an attempt to achieve the chromatographic separation. Although the complete separation of all six isomers was not achieved, the combination of mass spectral detector with liquid chromatography allowed qualitative identification of all analytes; The fragmentation mechanisms of the benzoic acid involve hydroxyl H/ortho H scrambling. This mechanism proposes that the carboxyl hydrogen and the ortho hydrogens of benzoic acids undergo partial exchange, and is used to suggest the formation of the m/e 123 ion formed during the fragmentation of the difluorobenzoic acids.

Keywords

Acids; Difluorobenzoic; HPLC; Identification; MS; Separation; HPLC/MS

Controlled Subject

Chemistry, Analytic

File Format

pdf

File Size

2068.48 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

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