مشخصات پژوهش

17-alpha-ethinyl estradiol (EE2) is the synthetic form of 17-beta estradiol, which is well known as steroid hormone. According to the literature, existence of steroid hormones in water and foods is a one of the main risk factors causing breast and prostate cancer [1]. Steroid hormones cause infertility and short stature in men as endocrine disrupters. So there is a vital need to develop sensitive and accurate methods for sample preparation and determination of steroid hormones in different samples [2]. In this study hollow fiber membranes mainly used in liquid-phase microextractions was used as solid-phase microextraction fiber. After loading n-octanol in the hollow fiber membrane pores, extraction time and temperature, type and volume of the desorption solvent, the ionic strength and pH were optimized. Quantitation was performed by HPLC-UV. Figures of the merit for the proposed method were presented below. Linear dynamic range and limit of detection of the method were 5-60 ppb and 1.70 ppb, respectively. The enrichment factors were between 45-65 (47.42 for 40 ppb and 63.80 for 5 ppb). The reproducibility of the method was evaluated for fiber preparation and microextraction processes. RSD% value for 5 fibers with identical preparation process was 4.61%, which show good fiber reproducibility. RSD% for microextraction process was calculated for 5 replicate determinations. 3.03%, indicates good repeatability of the microextraction process.