Determination of the fenvalerate insecticide in natural waters by a photochemically-induced fluorescence method

Abstract

<p>The fenvalerate pyrethroid insecticide was determined in various types of natural waters of Senegal by means of a newly-developed, simple, rapid and very sensitive photochemically-induced fluorescence (PIF) method. The PIF method was optimized with respect to the irradiation time, solvent and pH. The obtained calibration curves yielded correlation coefficients very close to unity. The limit of detection (LOD) and of quantification (LOQ) values were very low (LOD = 0.01–0.66 ng/ml and LOQ = 0.04–2.20 ng/ml, according to the solvent), and the relative standard deviation (RSD) values were small, ranging between 0.1 and 1.5 %, which indicated a very good analytical sensitivity and a great repeatability of PIF. Recovery studies were performed on spiked distilled water, tap water, sea water, well water, river water and draining water samples of Senegal, using the liquid-liquid extraction (LLE), solid phase extraction (SPE), and standard addition procedures. Satisfactory recovery results (about 85–121%) were obtained for the determination of fenvalerate in an aquatic environment.</p>