Direct Spectrofluorimetric Method for Analysis of Bifenthrin and Resmethrin Pyrethroid Insecticides in Senegalese Surface and Groundwater.

Abstract

This work examines bifenthrin (BIF) and resmethrin (RES), two pyrethroid insecticides used in the agricultural area of Niayes, focusing on their analysis in spiked surface and groundwater. Both pesticides have an optimal pH of 7 and an optimal MeOH concentration of 20% in water. Comparing fluorescence intensities across different solvents shows that it is higher in H₂O-MeOH for both BIF and RES. Calibration curves ranging from 0.15 to 7.5 µg mL^- 1 were established in different solvents, and their linearity was confirmed through variance analysis. The method measurement is highly sensitive, with LOD values ranging from 0.12 to 1.76 ng mL^- 1 and LOQ values ranging from 0.35 to 5.82 ng mL^- 1, depending on the medium and pesticide. The interday precision values range from 1.8 to 4.3%, attesting to the intermediate precision of the results. The mean recovery results for the determination of the two pesticides in spiked natural water were satisfactory, ranging from 96.2 to 103.7%, with an intraday precision value less than 5% attesting to the repeatability of the results. Moreover, the interference study shows the robustness of the method.