The application of planar optical waveguides to absorption spectrometry in flow injection analysis

Attenuated total reflection techniques have been used extensively as analytical tools for the analysis of thin films and analytes imbedded in complex scattering matrices. However they have not been commonly utilized as detectors in common analytical techniques such as Flow Injection Analysis because of their relatively low sensitivity. The feasibility of using a thin film planar waveguide as an absorption sensor in the Flow Injection Analysis of Urea was investigated. Urea was hydrolyzed to ammonia and carbon dioxide with the enzyme Urease. The ammonia produced was quantitated colorimetrically using Berthelot’s reaction. The reaction product, indophenol blue, was detected using the combination planar waveguide 9.2 microliter flow cell sensor. The planar waveguides used had 2 to 3 orders of magnitude greater sensitivity than typical internal reflection elements. The analytical working range obtained for urea determinations was from 0 to 20 mM urea at a rate of 30 samples per hour. A description of the investigation and the various factors involved in designing and optimizing a planar waveguide for absorption spectrometry is included.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1988

Author dc:creator

• Choquette, Steven Joseph

Chair dc:contributor.committeechair

• Dessy, Raymond E.

Committee members dc:contributor.committeemember

• Ward, Thomas C.
• Mason, John G.
• Dillard, John G.
• Long, G.L.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/53932

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/53932