Determination of Bendiocarb Insecticide by Reverse Flow Injection Analysis Using a Solid-Phase Reactor Containing Micro PbO2, Nano PbO2 and Grafted SiO2 - PbO2 Immobilized

Bendiocarb (BEN) is an acutely toxic carbamate insecticide which used in public places and agriculture, it is also effective against a wide range of nuisance and disease vector insects. A new rapid and sensitive reverse flow injection spectrophotometric procedure coupled with on-line solid-phase reactor is designed in this article for the determination of BEN in its insecticidal formulations and water samples, by using three different solid-phase reactors containing bulk PbO2 (B-SPR), PbO2 nanoparticles (N-SPR) and grafted nanoparticles of SiO2-PbO2 (G-SPR) immobilized on cellulose acetate matrix (CA). This method of oxidative coupling is based on alkaline hydrolysis of the BEN pesticide, and then coupled with N,N dimethyl-p-phenylenediamine sulphate (DMPD) to give a blue color product which measured at lambda(max) 675 nm. It worth to mentioned that under optimal conditions, Beer's law is obeyed in the range of 1-175 mu g mL(-1) for B-SPR and 0.25-70 mu g mL(-1) of BEN for both N-SPR and G-SPR respectively within limit of detection (LOD) of 0.931, 0.234 and 0.210 mu g mL(-1) for B-SPR N-SPR and G-SPR respectively. The surface methodology of the solid phase was also investigated by using atomic force microscopy.