On-trap derivatization of short-chain fatty acids

<p>It has recently been hypothesized that gastrointestinal microbiota modulate immune response by the production of short-chain fatty acids (SCFAs). There is a need for rapid, selective analytical methodology capable of trace analysis of SCFAs in complex biological matrices. Previous studies by others using multibed-sorbent traps, solid phase microextraction (SPME), and on-fiber derivatization with SPME showed that it is possible to achieve low limits of detection (LODs) for the gas chromatographic (GC) headspace analysis of SCFAs. The goal of this project was to achieve on-trap derivatization of SCFAs by incorporating a derivatizing agent onto a sorbent trap. Preconcentration and derivatization of acetic and propionic acids by the trap prior to entering a GC column produced FID signals for low ppb level concentrations of SCFAs that were competitive with mass spectrometry detection and followed a linear trend over two orders of magnitude. PDAM (1-pyrenyldiazomethane) impregnated poly(acrylate) was monitored on a daily basis and found to be stable up to ten days at room temperature when stored in an amber vial. The most significant challenge resulted from the manual construction of sorbent traps, which can negatively impact chromatographic reproducibility due to interfence of the flow of analytes and carrier gas both into and out of the trap. Alternative trap designs are under consideration to address this issue.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Open Access Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2011

Author dc:creator

• Mattieson, Mace

Contributors dc:contributor

• Heather Holmes, PhD, Chair
• Timothy Brewer, PhD
• Gavin Edwards, PhD

• tests of linearity
• sorbent traps
• flam ionization detector (FID)
• short-chain fatty acids
• Chemistry

Repository record dc:identifier

https://commons.emich.edu/theses/325

OAI identifier oai:identifier

oai:commons.emich.edu:theses-1323