title: Absorbance detection of amino acids by laser wave mixing in microbore liquid chromatography.
abstract: Nonlinear optical phase conjugation by degenerate four-wave mixing is demonstrated as a sensitive "absorbance" detection method for microbore high-performance liquid chromatography. An argon ion laser operating at the 488-nm line is used as the excitation light source to generate the wave-mixing signal for dabsyl-labeled amino acids. Advantages of the nonlinear laser detection method include: virtually 100% optical signal collection efficiency, generation of the signal in the form of a coherent laser beam, signal measurement against a virtually dark background, reliable detection of small absorbance values, excellent detection sensitivity for both fluorescing and non-fluorescing analytes, relatively simple one-color one-laser optical setup, and low power or energy requirements for continuous-wave or pulsed lasers. Using our one-laser one-color nonlinear laser detector for "absorbance" measurements in liquid chromatography, we report a crude preliminary "injected" detection limit of 780 fmol for glycine.
authors.affiliation: Department of Chemistry, San Diego State University, CA 92182, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Wu
authors.forename: W G
authors.initials: WG
authors.lastname: Tong
mesh_terms: D000465:Algorithms; D000596:Amino Acids / Q000032:analysis*; D002853:Chromatography, Liquid; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007834:Lasers; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives
chemical_list: D000596:Amino Acids; D007202:Indicators and Reagents; C010572:4-N,N-dimethylaminoazobenzene-4'-sulfonyl chloride; D004124:p-Dimethylaminoazobenzene