Investigation of Zeolitic Imidazolate Frameworks Ability as Sorbent in Stir Bar Sorptive Extraction Method

In this work, the zeolite imidazole framework-8 (ZIF-8) was initially synthesized by the solvothermal method. After confirmation of its structure, it was used to provide a new composite of acrylate-based polymer (PA) and ZIF-8 as a coating on a stir bar with suitable mechanical and chemical stability. Different manipulation methods was used for this purpose. This monolithic coated (PA/ZIF-8) devise was used in a stir bar sorptive extraction (SBSE) method. During the preparation of PA/ZIF-8 coating, the solvent type, the monomer to the solvent ratio, the monomer to cross linker ratio and the amount of ZIF-8 powder were optimized. In the optimization process, carvedilol (CAR) was used as a target compound and the extraction efficiency of this drug using proposed SBSE method was investigated by high performance liquid chromatography (HPLC) with photo diode array detector (PDA). In all steps, PA coated stir bar was also prepared for comparison of its extraction efficiency with PA/ZIF-8 coated stir bar. ). Repeatability in the production of ZIF-8/PA sorption coating on the stir bar was determined by calculating the relative standard deviation (RSD) of the extracted carvedilol field surface with three stir bar in a batch and in three different batch 6.6% and 6.96%, respectively. In order to investigate ability of optimized PA/ZIF-8 and PA coatings, haloperidol (HLP), losartan (LOS), loratadine (LOR), diazepam (DZ), nordiazepam (NDZ) and chlorpromazine (CPZ) were also tested as target compounds and their extraction efficiency were obtained. The results showed that HLP, LOS, LOR, DZ and NDZ are extracted on PA/ZIF-8 and PA coated stir bars at similar extraction and desorption conditions. But in the case of CAR and HLP, the use of PA/ZIF-8 stir bar showed an improvement of 100% in the concentration factor obtained from PA stir bar.Finally, effective parameters on extraction efficiency of CAR and HLP such as pH and volume of sample, extraction and desorption time and type of desorption solvent were optimized. Then the proposed method (monolithic PA/ZIF-8 coated-SBSE-HPLC-PDA) was validated and used for determination of CAR and HLP in human plasma samples.