Gradient elution isotachophoresis with direct ultraviolet absorption detection for sensitive amino acid analysis.
J Chromatogr A
; 1202(2): 203-11, 2008 Aug 22.
Article
en En
| MEDLINE
| ID: mdl-18644605
This work demonstrates coupling of the newly described electrophoretic enrichment technique of gradient elution isotachophoresis (GEITP) to a low-cost, conventional ultraviolet absorbance detector to realize sensitive measurements with a universal detector, eliminating the need for fluorescent analytes or derivatization. The effects of various parameters on enrichment were studied, including current density varied by leading electrolyte concentration, current density varied by applied electric field, and counter-flow acceleration across varying capillary inner diameters. Optimized parameters were applied to the enrichment and separation of the amino acids tryptophan (Trp) and tyrosine (Tyr). Limits of detection for Trp and Tyr were 51 and 215 nM, respectively, reflecting sensitivity enhancements of 860- and 1900-fold. Analysis times were less than 6 min, and peak height RSDs were less than 4%. A demonstration of enrichment and separation of these amino acids from artificial cerebrospinal fluid is additionally shown as a first step to realizing biochemical monitoring by GEITP.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrofotometría Ultravioleta
/
Aminoácidos
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
J Chromatogr A
Año:
2008
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos