title: Selective catalytic detection of dopamine.
abstract: Catalytic detection of dopamine in a flow-injection system based on a packed bed reactor containing immobilized tyrosinase is demonstrated. Electrochemical or photometric transduction of enzyme reaction products results in limits of detection (S/N = 3) of 3.5 +/- 1.4 microM (16.6 +/- 6.6 ng), and 8.4 +/- 3.5 microM (40 +/- 16.6 ng) respectively. The high catalytic efficiency of the reactor yields a diffusion-controlled system with a sample frequency of 450 h-1 when electrochemical transduction, 25 microliters injection volume and 0.9 ml min-1 flow rate are used. The catalytic system can be used in liquid chromatography post-column mode for the selective detection of dopamine in a complex mixture of drugs.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Ortega
authors.forename: E
authors.initials: E
authors.lastname: Domínguez
mesh_terms: D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000302:isolation & purification*; D004563:Electrochemistry; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D014442:Monophenol Monooxygenase; D010783:Photometry; D015203:Reproducibility of Results; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D014442:Monophenol Monooxygenase; D004298:Dopamine