title: Determination of azoxystrobin residues in grapes, musts and wines with a multicommuted flow-through optosensor implemented with photochemically induced fluorescence.
abstract: In this paper, the conversion of azoxystrobin in a strongly fluorescent degradation product by UV irradiation with quantitative purposes and its fluorimetric determination are reported for the first time. A multicommuted flow injection-solid phase spectroscopy (FI-SPS) system combined with photochemically-induced fluorescence (PIF) is developed for the determination of azoxystrobin in grapes, must and wine. Grape samples were homogenized and extracted with methanol and further cleaned-up by solid-phase extraction on C(18) silica gel. Wine samples were solid-phase extracted on C(18) sorbent using dichloromethane as eluent. Recoveries of azoxystrobin from spiked grapes (0.5-2.0 mg Kg(-1)), must (0.5-2.0 microg mL(-1)) and wine (0.5-2.0 microg mL(-1)) were 84.0-87.6%, 95.5-105.9% and 88.5-111.2%, respectively. The quantification limit for grapes was 0.021 mg Kg(-1), being within European Union regulations, and 18 microg L(-1) and 8 microg L(-1) for must and wine, respectively.
authors: Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Paraje Las Lagunillas, s/n, E-23071 Jaén, Spain.
authors: Javier López
authors: JL
authors: Flores
authors: Antonio Molina
authors: AM
authors: Díaz
authors: María L
authors: ML
authors: Fernández de Córdova
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D002623:Chemistry Techniques, Analytical / Q000379:methods; D005456:Fluorescent Dyes / Q000494:pharmacology; D005504:Food Analysis / Q000379:methods; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D010777:Photochemistry / Q000379:methods*; D011743:Pyrimidines / Q000737:chemistry*; D012984:Software; D013050:Spectrometry, Fluorescence / Q000379:methods*; D000073739:Strobilurins; D014466:Ultraviolet Rays; D027843:Vitis; D014920:Wine
chemical_list: D000935:Antifungal Agents; D005456:Fluorescent Dyes; D008689:Methacrylates; D011743:Pyrimidines; D000073739:Strobilurins; D008752:Methylene Chloride; C087670:azoxystrobin; D000432:Methanol