Stripping voltammetric analysis of organophosphate pesticides based on solid-phase extraction at zirconia nanoparticles modified electrode

A sensitive electrochemical stripping voltammetric method for analyzing organophosphate (OP) compounds was developed based on solid-phase extraction (SPE) at zirconia (ZrO2) nanoparticles modified electrode. ZrO2 nanoparticles were proved as a new sorbent for SPE of OP pesticides. Because of the strong affinity of ZrO2 for the phosphoric group, nitroaromatic OPs can strongly bind to the ZrO2 nanoparticle surface. The combination of SPE with square-wave voltammetry (SWV) provided a fast, sensitive, and selective electrochemical method for nitroaromatic OP compounds using methyl parathion (MP) as a model. The stripping response was highly linear over the MP range of 0.003–2.0 μg/mL, with a detection limit of 0.001 μg/mL. The fast extraction ability of ZrO2 nanoparticles makes it promising sorbent for various solid-phase extractions.