Investigation of using metal organic frameworks as solid phase

In this thesis, a method based on dispersive microsolid phase extraction (dSPE) was developed for di-2-ethylhexyl phthalate (DEHP) enrichment. Phthalates, known as endocrine disruptors, are easily transported to the environment due to their bond structure, causing accumulation in humans and other living organisms. Various institutions and organizations such as the Turkish Food Codex and the European Food Safety Authority (EFSA) have migration limits for phthalates. In this context, it is of great importance to monitor the transmission of phthalate to various food and environmental samples and related environmental effects. DEHP was enriched with the synthesized metal-organic framework (MOF-5) and analyzed by gas chromatography (GC-MS) with detector mass spectrometry. The structural properties of the adsorbent synthesized under the conditions specified in the literature were characterized using Fourier transform infrared spectroscopy (FT-IR) technique, X-ray diffractometry (XRD) and scanning electron microscopy (FESEM). The model solution was used to optimize the solid phase extraction. The solid phase amount, elution solvent type and volume, pH, salt amount and sample volume parameters were scanned under operating conditions. At the end of the studies carried out in this context, DEHP retained with 15 mg MOF-5 in 10 mL sample volume was eluted with 0,5 mL Methanol:Acetonitrile (1:1 ratio). Under these conditions, the LOD and LOQ values for DEHP were calculated as 5,3 ng mL-1 and 17,5 ng mL-1, respectively. The enrichment factor of the method was found to be 20, the quantitative recovery was >%90 and the regression value of the calibration chart was determined as 0.9993. The method has been applied to a variety of food and environmental samples, including tap water, mineral water, sea water and industrial wastewater. In order to test the accuracy of the method, standard additions were made to some real samples an the recoveries were calculated over 90%. In addition, the adsorption capacity and isotherm studies were also carried out, the adsorption capacity was 16,26 mg/g and it was observed that the isotherm conformed to the Langmuir isotherm for MOF-5, that is, it adsorption in a single layer.