Solid phase microextraction (SPME) is one of the modern microextraction techniques, which is introduced by Pawliszyn in 1990. In this technique, a coated fiber with a small amount of prepared absorbent is used for the extraction and preconcentration of target analytes in only one step . As far as indicated in previously published articles, SPME has some advantages including ease of operation, quickness, considerable extraction ability and reduction of solvent consumption. SPME is a useful microextraction method. In this method, the small amount of coated absorbent lead to a low sensitivity, which is the main drawback of the miniaturized technique. In this case, increment of the coating thickness can be beneficial. Since SPME is based on equilibrium, increasing the thickness of the coating causes the increase of equilibrium time . The main goal of the current work is to electrodeposite the LDH on the surface of the pencil graphite electrode and convert the prepared template into the Co3O4 as the absorbent. The fiber will be used as the absorbent in SPME of diazinon and it will be quantified by HPLC-UV.
