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Abstract
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In this research, the complexation of a recently synthesized covalent organic framework (schiff base network1) with Hg2+ was investigated by IR and FMO computations. The obtained theoretical results showed the complexation process is experimentally feasible, exothermic, spontaneous, and thermodynamically favorable and schiff base network1 can be used as an ionophore for the development of a potentiometric sensor to determination of Hg2+. Therefore, an Hg2+ selective PVC membrane coated graphite electrode was developed based on schiff base network1. The best response was observed form the membrane composition of PVC (32%), Nitrobenzene (60%), sodium tetraphenylborate (2%), and schiff base network1 (6%). The designed sensor showed an excellent Nernstian response to Mercury (II) (29.8 mV. Decade-1) over a wide concentration range from 1×10-7 to 5×10-3 mol L-1 and the detection limit of the proposed potentiometric sensor was 80 nmol L-1 (16.05 ppb). The effect of different interfering species on the potentiometric response of the suggested electrode was scrutinized by matched potential method (MPM) and no interference was observed. The performance of the developed electrode in partially nonaqueous mediums was also checked out and the obtained results showed the electrode can also be utilized in systems containing %20 organic solvents (ethanol and acetone). The response time and lifespan of the electrode were < 10 S and 16 weeks respectively. In the end, the analytical performance of the fabricated sensor for the determination of Hg (II) in three different industrial effluent samples was scrutinized and the obtained results were compared with a standard spectrophotometric technique
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