title: Separation of aromatic acids, DOPA, and methyl-DOPA by capillary electrophoresis with dendrimers as buffer additives.
abstract: Polyamidoamine starburst dendrimers with terminal carboxylate groups are used as a pseudo-stationary phase in electrokinetic chromatography for separating the selected aromatic amino acids phenylalanine, phenylglycine, homophenylalanine, and tyrosine and the catecholamines 3-(3,4-dihydroxyphenyl)alanine and 3-(3,4-dihydroxyphenyl)-2-methylalanine at different pH levels. A significant difference in analyte selectivity is observed between dendrimers of different generations and at different pH levels. At pH 7.0, the utility of the dendrimers for separating these analytes is limited by relatively low selectivity and a noisy baseline. However, good separation and selectivity are obtained with low generation dendrimers (G0.5 and G1.5) at low pH. Strong association of the solute with dendrimers is observed for high generations (G2.5, G3.5, and G5.5).
authors.affiliation: Department of Chemistry, University of Cincinnati, OH 45221-0172, USA.
authors.forename: H
authors.initials: H
authors.lastname: Gao
authors.forename: J
authors.initials: J
authors.lastname: Carlson
authors.forename: A M
authors.initials: AM
authors.lastname: Stalcup
authors.forename: W R
authors.initials: WR
authors.lastname: Heineman
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002021:Buffers; D002264:Carboxylic Acids / Q000302:isolation & purification*; D050091:Dendrimers; D004295:Dihydroxyphenylalanine / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary; D006863:Hydrogen-Ion Concentration; D008750:Methyldopa / Q000302:isolation & purification*; D011073:Polyamines / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001672:Biocompatible Materials; D002021:Buffers; D002264:Carboxylic Acids; D050091:Dendrimers; C104700:PAMAM Starburst; D011073:Polyamines; D008750:Methyldopa; D004295:Dihydroxyphenylalanine