Abstract
Lead is a toxic heavy metal poses a significant health risk. Lead pollution is a global problem, that recognizes no geographical or political boundaries. For this, we must harness efforts to combat this risk, which claimed thousands of lives, especially in children. This research is a contribution to serve the humanity, by introducing a simple analytical method for the determination of lead(II) in environmental and food samples. The presence of lead at trace levels in environmental and food samples imposes the need to use very sensitive, accurate, precise, fast and selective analytical methods for its determination. These required characteristics are successfully achieved by the proposed method in this work, which also features with simplicity and low cost. The method proposed in this work introduces a novel potentiometric sensor based on a plasticized polymeric membrane incorporating lead(II)-gallocyanine (PbGC2) imprinted polymer as the sensing element for selective recognition and determination of lead(II) ions. After dozens of experiments and many challenges that are outlined in this study, it was concluded that the best composition of the selective membrane included 1.5 wt.% of imprinted particles from methacrylic acid monomers (MAA/IIP) and 2:1 (DBS plasticizer:PVC). This sensor exhibited the best performance with a limit of detection of 4.5x10-7 M and a slope of 44.2 mV/decade over the concentration range of 8.3x10-7 - 1.5x10-5 M at pH 7.55 for the sample solution. The response time of the sensor was less than 30 s, and the sensor was used for a period of two weeks without a significant divergence in potentials. The sensor offered high selectivity toward lead(II) ions over various interferent ions, such as Mg2+, Co2+, Sr2+, Ni2+, Ca2+ , Ba2+, Cu2+ and Hg2+. The proposed sensor has been successfully applied to the analysis of several food and environmental samples...
