Concentration and separation of hypoglycemic drugs using solid-phase extraction-capillary electrophoresis

M. A. Strausbauch, S. J. Xu, J. E. Ferguson, M. E. Nunez, D. Machacek, G. M. Lawson, Peter J. Wettstein, James P. Landers

Research output: Contribution to journalArticle

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Abstract

Solid-phase extraction-capillary electrophoresis (SPE-CE) is a technique whereby very dilute analytes may be selectively extracted from a sample matrix and concentrated on-line for analysis. This study describes the first phase in the development of a method exploiting this technique for the direct analysis of hypoglycemic drugs in urine. Effective separation and detection of six sulfonylurea drug standards at concentrations below the detection limit of conventional capillary electrophoretic techniques is shown to be attainable. Since surfactant interfered with the on-line concentration process, non-MEKC (micellar electrokinetic chromatography) separation conditions were defined. Using 250 mM borate/5 mM phosphate at pH 8.4, all drugs in a mixture at 285 ng/ml were effectively extracted, concentrated from an injected volume of 2.5 μl, non-selectively desorbed with an organic-based elution buffer and electrophoretically resolved. Sample loading was found to be linear in the 0.12-1.9 μl range and drugs in a volume of up to 190 μl could be concentrated and detected with a sensitivity of ≈5 ng/ml. Not only was resolution of the desorbed material uncompromised by the presence of the SPE-tip, but separation of glipizide and glyburide was observed despite the fact that these drugs were unresolved under the same separation conditions by standard capillary zone electrophoresis (CZE). From these results, it is clear that SPE-CE not only increases the sensitivity for detection but that selectivity may be altered due to chromatographic processes occurring on the solid-phase resin.

Original languageEnglish (US)
Pages (from-to)279-291
Number of pages13
JournalJournal of Chromatography A
Volume717
Issue number1-2
DOIs
StatePublished - Nov 24 1995

Fingerprint

Capillary electrophoresis
Solid Phase Extraction
Capillary Electrophoresis
Hypoglycemic Agents
Pharmaceutical Preparations
Glipizide
Borates
Glyburide
Chromatography
Electrophoresis
Surface-Active Agents
Limit of Detection
Buffers
Resins
Phosphates
Urine

ASJC Scopus subject areas

  • Biochemistry
  • Analytical Chemistry
  • Organic Chemistry

Cite this

Strausbauch, M. A., Xu, S. J., Ferguson, J. E., Nunez, M. E., Machacek, D., Lawson, G. M., ... Landers, J. P. (1995). Concentration and separation of hypoglycemic drugs using solid-phase extraction-capillary electrophoresis. Journal of Chromatography A, 717(1-2), 279-291. https://doi.org/10.1016/0021-9673(95)00743-6

Concentration and separation of hypoglycemic drugs using solid-phase extraction-capillary electrophoresis. / Strausbauch, M. A.; Xu, S. J.; Ferguson, J. E.; Nunez, M. E.; Machacek, D.; Lawson, G. M.; Wettstein, Peter J.; Landers, James P.

In: Journal of Chromatography A, Vol. 717, No. 1-2, 24.11.1995, p. 279-291.

Research output: Contribution to journalArticle

Strausbauch, MA, Xu, SJ, Ferguson, JE, Nunez, ME, Machacek, D, Lawson, GM, Wettstein, PJ & Landers, JP 1995, 'Concentration and separation of hypoglycemic drugs using solid-phase extraction-capillary electrophoresis', Journal of Chromatography A, vol. 717, no. 1-2, pp. 279-291. https://doi.org/10.1016/0021-9673(95)00743-6
Strausbauch, M. A. ; Xu, S. J. ; Ferguson, J. E. ; Nunez, M. E. ; Machacek, D. ; Lawson, G. M. ; Wettstein, Peter J. ; Landers, James P. / Concentration and separation of hypoglycemic drugs using solid-phase extraction-capillary electrophoresis. In: Journal of Chromatography A. 1995 ; Vol. 717, No. 1-2. pp. 279-291.
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