title: Capillary electrophoresis with a UV light-emitting diode source for chemical monitoring of native and derivatized fluorescent compounds.
abstract: We report the utilization of a high power UV light-emitting diode for fluorescence detection (UV-LED-IF) in CE separations. CE-UV-LED-IF allows analysis of a range of environmentally and biologically important compounds, including PAHs and biogenic amines, including neurotransmitters, amino acids, proteins, and peptides, that have been derivatized with UV-excited fluorogenic labels, e.g., o-phthalic dicarboxaldehyde/beta-mercaptoethanol (OPA/beta-ME). The 365 nm UV-LED was used as a stable, low cost source for detection of UV-excited fluorescent compounds. UV-LED-IF was used with both zonal CE separations and MEKC. Native fluorescence detection of PAHs was accomplished with detection limits ranging from 10 nM to 1.3 microM. Detection limits for OPA/beta-ME-labeled glutamic acid and aspartic acid were 11 and 10 nM, respectively, for off-line labeling, and 47 and 47 nM, respectively, for on-line labeling, comparable to UV-laser-based systems. Analysis of OPA/beta-ME-labeled proteins and peptides was performed with 28 and 47 nM detection limits for BSA and myoglobin, respectively.
authors.affiliation: Department of Chemistry, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Suminda
authors.initials: S
authors.lastname: Hapuarachchi
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Janaway
authors.forename: Craig A
authors.initials: CA
authors.lastname: Aspinwall
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005456:Fluorescent Dyes / Q000032:analysis*; D009211:Myoglobin / Q000302:isolation & purification; D010446:Peptide Fragments / Q000302:isolation & purification; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification; D011506:Proteins / Q000032:analysis / Q000302:isolation & purification; D012710:Serum Albumin, Bovine / Q000302:isolation & purification; D014466:Ultraviolet Rays; D009764:o-Phthalaldehyde / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D005456:Fluorescent Dyes; D009211:Myoglobin; D010446:Peptide Fragments; D011084:Polycyclic Aromatic Hydrocarbons; D011506:Proteins; D012710:Serum Albumin, Bovine; D009764:o-Phthalaldehyde