Methods of detecting the presence of toxins in a sample using electrophoretic separations and of performing electrophoretic separation of complex samples are provided. The method of detecting the presence of toxins includes reacting a sample and a substrate with a signaling enzyme which converts the substrate to the product in a reaction medium introducing a run buffer into a separation channel having an inlet end selectively introducing at least one of the substrate and the product of the reaction medium into the inlet end of the separation channel electrophoretically separating the substrate and the product and determining the rate of conversion of the substrate to the product wherein a change in the rate of conversion is indicative of the presence of toxins.
This technology can be applied to the detection of pesticides or other toxins in difficult sample matrices with minimal sample preparation. Other applications include food and soil safety purposes.