SEPARATION MECHANISM OF PESTICIDES BY CAP ILLARY ELECTROPHORESIS USING O W MICROEMULSIONS AS A MIGRATING SOLUTION/

Four kinds of pesticides (MEP, IBP, MCP, and PCNB) were separated by t he capillary electrophoresis with some o/w microemulsions (mu E-CE). I n order to obtain information concerning the separation and/or migrati on mechanism mu E-CE was carried out. The longest migration time for M CP was found in the case of surfactants with a sulfonate group, while the use of ones with a sulfate group led to the shortest migration tim e for MCP. The characteristic effect of the surfactants on the migrati on of MCP suggested a specific interaction with the interface of the m icroemulsion droplets. To obtain more detailed information about the m icroenvironment of the organophosphorus pesticides incorporated into t he microemulsion, P-31-NMR measurement was carried out. It was found t hat a adsorption on the interface of the droplet contributed to a pred ominant interaction between the microemulsion and MEP, while in IBP th e distribution into the droplet played an important role.