Chemiluminescence determination of organophosphorus pesticides chlorpyrifos in vegetable

A novel chemiluminescence method for the quantitative assay of the organophosphorus pesticide chlorpyrifos in vegetable samples is presented. The determination is based on the reaction of chlorpyrifos with luminol-H2O2 in alkaline medium with sodium chloride being enhancer. Under the optimum conditions, the increased CL intensity was proportional with the concentration of chlorpyrifos in the range of 1.0 x 10(-8) g . ml - 1.0 x 10(-6) g . ml(-1) and the detection limit was 3.5 x 10(-9) g . ml(-1) (3 sigma). The relative standard is less than 3.9% for 5.0 x 10(-7) g . ml(-1) chlorpyrifos (n = 7). This method has been successfully applied to the determination of chlorpyrifos residue in vegetable sample. Further study was focused on the mechanism of chlorpyrifos and the possible mechanism was proposed.