High-performance liquid chromatographic determination of phenylureas by photochemically-induced fluorescence detection.
A HPLC method, using photochemically-induced fluorescence detection, is described for the separation and determination of four phenylurea herbicides including diuron, isoproturon, linuron and neburon. A post-column photoreactor, consisting of a reactor knitted around a 4 W xenon lamp, has been included between the column and the detector, in order to transform the non-fluorescent herbicides into fluorophors. The influence of mobile phase composition, flow-rate, pH, and buffer concentration has been studied. An acetonitrile-buffer solution of potassium phosphate dibasic of pH 7 and 0.01 M concentration (60:40, v/v), was selected as optimum. For the fluorimetric detection, optimal excitation/emission wavelengths 324/403, 301/433, 335/411 and 326/385 nm were selected for the determination of diuron, isoproturon, linuron and neburon, respectively. The detection limits ranged between 0.07 and 0.46 microg/ml, according to the compound.
Muñoz de la Peña
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Department of Analytical Chemistry, Faculty of Sciences, University of Extremadura, Badajoz, Spain. arsenio@unex.es
Mahedero
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MC
Bautista-Sánchez
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D002021:Buffers; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D010671:Phenylurea Compounds / Q000032:analysis*; D010777:Photochemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*
D002021:Buffers; D006540:Herbicides; D010671:Phenylurea Compounds