SUITABILITY OF MICROWAVE-ASSISTED EXTRACTION FOR MULTIRESIDUE PESTICIDE ANALYSIS OF PRODUCE

A systematic study of the microwave-assisted extraction of field-incur red pesticide residues from several crop matrices was conducted. Five crops consisting of beets, cucumbers, lettuce, peppers, and tomatoes w ere grown and treated in the field with seven pesticides, dacthal, chl orpyrifos, chlorothalonil, diazinon, permethrin, methoxychlor, and azi nphos-methyl. Values were determined for the microwave extraction para meters, time and temperature, which resulted in efficient recovery ove r the selected pesticides and crops. The microwave settings were shown to be dependent on both crop matrix and pesticide. Recovery of the fu ngicide chlorothalonil was highly dependent on temperature, while the remaining pesticides tested were not so demanding. Using the selected microwave time and temperature values, pesticide recoveries from the m icrowave method were then compared with those of the conventional meth od. Statistical comparison of pesticide recoveries and method reproduc ibility of the microwave method versus the conventional blender extrac tion indicated that microwave extraction data compare favorably with c onventional extraction data.