Thin film microextraction is one of the solid phase microextraction techniques that has attracted a great attention due to its simplicity, efficiency and being environmentally friendly. In this method, usually a thin commercially provided membrane is used as the extraction tool. The main focus of this work is to introduce a new method for preparing thin film. In this method a suspension of nylon 6 (as the thin film substrate), octadecylsilane (as the thin film sorbent) and poly ethylene glycol (as disperser agent) was prepared and after being homogenized by sonication, it was poured on a Petri dish flat surface. After evaporation of the solvent, the dried thin film was cut in a special form and was used for extraction of bisphenol A as an endocrine disrupting chemical. In order to obtain the highest extraction yield, several thin films were prepared by using nylon 6 and clay, LiChrolut EN and multiwall carbon nano tube separately as sorbent, and then compared with the octadecylsilane prepared thin film. To reduce the volume of organic solvent used in this method, special desorption vials were prepared from glass pipe with maximum volume of 350 micro liters. The thin film is rolled in desorption vial using a pair of tweezers. After optimizing the extraction method, an hour extraction of bisphenol A from its salt less solution and then desorption of analyte from the thin film using 150 micro liters of methanol solvent was chosen as the ideal extraction condition. High performance liquid chromatography with ultraviolet detector was used for the sake of chromatographic analysis. Detection limit, dynamic range and relative standard deviation of investigated method were reported as 0.8 , 1-1000 and 2.9 to 6.9 percent respectively. Finaly, four real samples obtained from baby bottle, Isfahan Zayandeh Rood River, waste water from foolad mobarake of Isfahan and refinery of Shahin Shahr were used inorder to evaluate the method. After spiking the mentioned real samples in two 10 and 50 level concentrations, relative recoveries and RSDs were obtained about 76-120 and 2.2-14 percent respectively.
