Application of Tris(2,2'-Bipyridyl)ruthenium(ii) Electrogenerated Chemiluminescence for Detection in Liquid Chromatography

This research has involved the application of tris(2,2$\sp\prime$-bipyridyl)ruthenium(II) (Ru(bpy)$\sb3\sp{2+}\rbrack$ electrogenerated chemiluminescence (ECL) detection to liquid chromatography (LC) and microbore LC. An important class of compounds that can be detected using Ru(bpy)$\sb3\sp{2+}$ ECL is amines, which are often difficult to detect by conventional methods without derivatization. Ru(bpy)$\sb3\sp{2+}$ ECL offers a very sensitive and selective detection method for many amines without the need for derivatization. The effect of hydrodynamics on CL emission was investigated for the Ru(bpy)$\sb3\sp{2+}$ ECL system. For slow reactions, maximum CL emission is obtained at low linear velocities, and for fast reactions, maximum CL emission is obtained at high linear velocities. This is important information for the optimization of CL detection in LC. Ru(bpy)$\sb3\sp{2+}$ ECL can be used for detection in LC with either the CL reagent added post-column or included in the mobile phase. The effect of adding Ru(bpy)$\sb3\sp{2+}$ to the mobile phase was investigated for the separation of the herbicide glyphosate and several structurally related compounds. Some Ru(bpy)$\sb3\sp{2+}$ is retained on the column causing retention times to decrease, but the separation is not affected drastically. Since Ru(bpy)$\sb3\sp{2+}$ can be included in the mobile phase without drastically affecting the separation, Ru(bpy)$\sb3\sp{2+}$ ECL can be applied to detection with microbore LC. Ru(bpy)$\sb3\sp{2+}$ ECL detection was applied to the determination of the antibiotic erythromycin and the anxiolytic drug buspirone in blood plasma and urine samples using microbore LC. Due to Ru(bpy)$\sb3\sp{2+}$'s unique selectivity, minimal sample preparation is required before analysis of these complex biological samples. An alternative to including Ru(bpy)$\sb3\sp{2+}$ in the mobile phase for LC detection would be to immobilize Ru(bpy)$\sb3\sp{2+}$ at the electrode surface. At this time, there is not a reliable technique for the immobilization of Ru(bpy)$\sb3\sp{2+}.$ Some of the problems associated with the currently used techniques might be due to the potential that must be applied for ECL. Tris(2,2$\sp\prime$-bipyridyl)osmium(II) (Os(bpy)$\sb3\sp{2+}\rbrack,$ a structurally similar compound to Ru(bpy)$\sb3\sp{2+},$ has an oxidation potential much lower than Ru(bpy)$\sb3\sp{2+}$ and was investigated as an alternative ECL reagent. Due to low CL emission intensity, it was found that Os(bpy)$\sb3\sp{2+}$ is unsuitable as an alternative analytical ECL reagent for Ru(bpy)$\sb3\sp{2+}.$.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Ridlen, Jennifer Sue

Contributors dc:contributor

• Nieman, T.A.

• Chemistry, Analytical

Language dc:language

eng

Identifier

(MiAaPQ)AAI9737235

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84369