Separation and Determination of Diethyl phthalate in Water Samples Based on STA- 16(Fe) as an Efficient Sorbent

Abstract

Diethyl phthalate (DEP) belongs to the family of phthalates or phthalic acid esters (PAEs). Diet is considered as the main source of PAE exposure [1,2]. PAEs are known to be potential endocrine disruptors, accumulate in tissues, and are not well degradable. Therefore, determination of DEP is an important analytical task. In this study, STA-16 (Fe) was synthesized [3] and characterized by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analysis. STA-16 (Fe) as adsorbent, in dispersive micro-solid phase extraction (Dµ-SPE) as green, simple and efficient method was used for trace quantification of diethyl phthalate. Four independed parameters of pH, adsorbent amount, temperature and ultrasonic time were selected as factors influencing the process and optimized by central composite design (CCD) [4]. In Dµ-SPE method, a solution containing the appropriate amount of DEP was placed in a 30 mL centrifuge tube. The pH of the sample solution was adjusted to 7, then the adsorbent was dispersed in the sample solution by ultrasonic device and the adsorbed analytes were eluted with a 0.5 mL of acetonitrile-nitric acid 65% 0.2 M (50/50 ratio). By separating the adsorbent from the solution the analyte solution is transferred to the spectrofluorimetry cell. Under optimal conditions, linear range of 25-550 ng mL-1, detection limit of 7.33 ng mL-1 and relative standard deviation (R.S.D) of 0.36% were obtained for the DEP. Finally, the proposed method was successfully used for preconcentration and determination of DEP in water samples.