Determination of Pesticide Residues in Cereals by Liquid Chromatography and UV Detection

A chromatographic method to determine pesticide residues in cereals by high-performance liquid chromatography (HPLC) and ultraviolet (UV) detection has been described. The study focused on the preliminary purification procedure because of the analytical problems associated with the presence in these food matrices of high-molecular-weight compounds, such as lipids, triglycerides, celluloses, and starch, which can interfere and reduce the chromatographic separation efficiency of the analytes. The method proposed is based on the extraction of pesticide residues from 5 g of sample extracted with the use of petroleum ether and on cleanup with a C18 cartridge. The pesticides were eluted with acetonitrile. The column packed with solid support was eluted with a suitable solvent, and only a portion of flow outlet side of the UV detector was collected. Using the information of standard UV trace, it was possible to establish an appropriate portion and to ensure the collection of all pesticides analyzed. The simple and rapid proposal method has shown good recovery (70–110%) for different spiked levels of samples (0.025–0.1 mg=Kg) and could be applied to other food matrices that containing high-molecular-weight compounds.