title: Indirect pulsed electrochemical detection of aliphatic carboxylate-containing analytes following high performance anion-exchange chromatography.
abstract: The mechanism of detection in pulsed electrochemical detection (PED) requires preadsorption of the analyte to the working electrode prior to its subsequent oxidation. Indirect detection is accomplished by the addition of a PED-active reagent to the mobile phase, whose signal is attenuated by an analyte that more strongly adsorbs to the electrode surface. Here, indirect PED (InPED) is applied to the determination of aliphatic carboxylate-containing compounds separated using high performance anion-exchange chromatography (HPAEC). Limits of detections of 0.05-2 ppm (10-400 pmol) are found for most analytes tested using an optimized potential-time waveform at a gold working electrode. The analytical utility of InPED is demonstrated for assays of gabapentin, biotin, proline and several over-the-counter formulations.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States.
authors.forename: Loryn R
authors.initials: LR
authors.lastname: Keating
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States. Electronic address: lacourse@umbc.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: LaCourse
keywords: Anion-exchange; Biotin; Chromatography; Gabapentin; Indirect detection; Pulsed electrochemical detection