Determination of Silver Ion in Water Wamples Using Potentiometric Sensor Based on Molecularly Imprinted Polymer

For over three decades now, molecularly imprinted polymers have successfully been used for selective chemical sensing because the shape and size of their imprinted molecular cavitiesperfectly matched those of the target analyte molecules [1]. Due to the molecular recognition ability, MIPs have been proposed for promising applications in a wide variety of fields, such as chemical/biological sensors, chiral separation, catalyst, and solid-phase extraction [2].Silver is an important element that is widely used for human life. It is obvious that in order to monitor silver concentration in natural waters and to study silver toxicity effects on bio organisms in oceanographic research and survey work, highly sensitive and selective methods for silver determination are required. Conventional techniques which have been applied to the extraction of soluble silver metal from its solutions include solvent extraction, precipitation, ionexchange and electrodeposition. The majority of these techniques have shortcomings such as high cost, poor selectivity, extensive labor, and time consumption. In the last decade significant research effort have been directed towards techniques improving the selective extraction of silverions; and ion imprinted polymeric materials with different functional groups have been frequently used[3]. A silver ion selective electrode (ISE) based on an ion-imprinted polymer (IIP) as a novel ionophore has been prepared and studied. The ion-selective electrode (ISE) was prepared bydispersing silver (IIP) particles in dibutyl phthalate as a plasticizer and then embedding them in a polyvinylchloride polymeric matrix. The silver (ISE) showed a nernstian response for silver over the dynamic concentration range of 1.0 × 10−5 mol L−1 – 1.0 × 10−2 mol L−1, with a slope of67.2 mV per decade. The limit of detection was 1.0 × 10−7 M. The proposed electrode revealed good selectivity over a wide variety of other cations including alkali, alkaline earth, heavy and transition metals. The accuracy of the proposed electrode was checked through the analysis of spiked water samples.

Keywords:

Silver , Molecularly imprinted polymers , Cation