title: A microchip electrophoresis device with on-line microdialysis sampling and on-chip sample derivatization by naphthalene 2,3-dicarboxaldehyde/2-mercaptoethanol for amino acid and peptide analysis.
abstract: The integration of rapid on-chip sample derivatization employing naphthalene 2,3-dicarboxaldehyde and 2-mercaptoethanol (NDA/2ME) with an easily assembled microdialysis/microchip electrophoresis device was carried out. The microchip device consisted of a glass layer with etched microfluidic channels that was sealed with a layer of poly(dimethylsiloxane) (PDMS) via plasma oxidation. This simple sealing procedure alleviated the need for glass thermal bonding and allowed the device to be re-sealed in the event of blockages within the channels. The device was used for analysis of a mixture of amino acids and peptides derivatized on-chip with NDA/2ME for laser-induced fluorescence (LIF) detection. A 0.6 mM NDA/1.2 mM 2ME mixture was simply added into the buffer reservoir for dynamic on-column derivatization of sample mixtures introduced at a flow rate of 1.0 microl/min. Using this scheme, sample injection plugs were derivatized and separated simultaneously. Injections of ca. 12 fmol of 5 mM amino acid and peptide samples were conducted using the system. Finally, a three-component mixture of Arg, Gly-Pro, and Asp was sampled from a vial using microdialysis, derivatized, separated and detected with the system. The ultimate goal of this effort is the creation of a micro-total analysis system for high-temporal resolution monitoring of primary amines in biological systems.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Avenue, Lawrence, KS 66047, USA.
authors.forename: Bryan H
authors.initials: BH
authors.lastname: Huynh
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Fogarty
authors.forename: Pradyot
authors.initials: P
authors.lastname: Nandi
authors.forename: Susan M
authors.initials: SM
authors.lastname: Lunte
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D008623:Mercaptoethanol / Q000737:chemistry*; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods; D009281:Naphthalenes / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*
chemical_list: D000596:Amino Acids; D009281:Naphthalenes; D010455:Peptides; D008623:Mercaptoethanol; C027717:2,3-naphthalenedicarboxaldehyde