title: A flow-through optosensing device with fluorimetric transduction for rapid and sensitive determination of dipyridamole in pharmaceuticals and human plasma.
abstract: A flow-through optosensor with fluorimetric transduction has been prepared for the sensitive and selective determination of dipyridamole in aqueous solutions and biological fluids. The method is based on a monochannel flow-injection analysis system using Sephadex QAE A-25 resin, placed into a Hellma 176-QS fluorimetric flow-through cell, as an active sorbing substrate. The native fluorescence of dipyridamole fixed on the solid sorbent is continuously monitored at wavelengths of 305 and 490 nm for excitation and emission, respectively. After obtaining the maximum fluorescence intensity, the eluent solution (KH(2)PO(4)/NaOH buffer solution, c(T)=0.05 mol l(-1), pH 6.0) is allowed to reach the flow cell, the analyte is removed, and the resin support is regenerated. When an NaOH (10(-4) mol l(-1))/NaCl (0.1 mol l(-1)) solution is used as carrier solution, at a flow-rate of 1.56 ml min(-1), the sensor responds linearly in the measuring range of 10-500 microg l(-1) with a detection limit of 0.94 microg l(-1) and a throughput of 22 samples per hour (300 microl of sample volume). The relative standard deviation for ten independent determinations (200 microg l(-1)) is less than 0.82%. The method was satisfactorily applied to the determination of dipyridamole in pharmaceutical preparations and human plasma.
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Paraje Las Lagunillas ED. 5, 23071, Jaén, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ruiz-Medina
authors.forename: M L
authors.initials: ML
authors.lastname: Fernández-de Córdova
authors.forename: A
authors.initials: A
authors.lastname: Molina-Díaz
mesh_terms: D002626:Chemistry, Pharmaceutical; D004176:Dipyridamole / Q000097:blood / Q000737:chemistry*; D017022:Flow Injection Analysis / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007475:Ion Exchange Resins / Q000737:chemistry; D010726:Phosphodiesterase Inhibitors / Q000097:blood / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods
chemical_list: D007475:Ion Exchange Resins; D010726:Phosphodiesterase Inhibitors; D004176:Dipyridamole