Pesticide analysis by MEKC on a microchip with hydrodynamic injection from organic extract

An integrated microchip for monitoring carbamate pesticides in environmental water using continuous flow chemical processes is under development, i.e., the integration of hydrolysis, azo-derivatization, liquid-liquid extraction, electrophoretic separation, and quantification. The separation of the derivatives of four carbamate pesticides (carbaryl, carbofuran, propoxur, and bendiocarb) extracted in the continuous flow of a 1-butanol phase was studied in a silica microchip using micellar EKC. A baseline separation of four pesticide derivatives was achieved on a silica chip using hydrodynamic injection with electroosmotic gating. Detection using a thermal lens microscope showed good linearity in the concentration range of 10^-6-10^-5 M with an LOD of 5 × 10^-7 M, which is superior to that of conventional CE with UV absorption detection at a level of 10^-4 M.