New Method for Determination of Mercury in Contaminated Water by using Nano Composite Carbon Paste Electrode

In this research, we constructed chemical sensor for determining mercury in contaminated water because we needed fast, simple, low-cost, and accurate determination of mercury in different environmental systems. Although several methods have been developed for determination of mercury ion in contaminated water, there is no a cheap, simple, accurate and rapid method to measure this ion. Aim of this study is to develop a new method to measure the mercury based on using nanosilica, multi-walled carbon nanotube (MWCNT) and 1,13-Bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane (Kryptofix 5) as an ionophore for modification of a CPE. The optimum composition of modified CPE was determined as 63.6% of graphite powder, 25% of paraffin oil, 4% of multiwalled carbon nanotube (MWCNT), 0.4% nanosilica and 7% of ionophore. This optimum composition was shown high selectivity, with appropriate Nernestian slope (29.5 ± 0.4mV/decade), linear range (from 1.0×10-2to 1.0×10-8M), with a detection limit of (2.0×10-9M), The response of the sensor is independent of pH in the range of 3.1 – 8.4, and The interference of different ionic species with the response of the electrode shows a good selectivity of the proposed sensor The proposed sensor is successfully applied in determination of mercury ions in some contaminated water samples. The results of this study to introduce a cheap accurate and simple method for determination of mercury ion in contaminated water.