New Carbon Paste Modified Micro Electrode Based on Haematoxylin for Determination of Aluminum in Underground Water

摘要

A novel, simple and highly sensitive micro electrode based on carbon paste modified withhaematoxylin (HCPME) was suggested for the determination of aluminum. HCPME was prepared bymixing graphite powder and haematoxylin with hot paraffin oil. The surface of the prepared electrodewas characterized using scanning electron microscope (SEM). Various experimental parameters,which influenced the electrochemical behavior of HCPME, were optimized. Applying the cyclicvoltammetric technique under the optimized conditions, HCPME gave one anodic oxidation peak at +0.77 V and one reduction cathodic peak at + 0.0 V (vs. Ag/AgCl reference electrode). The proposedmethod relies on the linear decease of the cathodic peak of haematoxylin offered by square wavevoltammogram (SWV) with the addition of Al(III), while the peak potential remains the same. A linear-9 -2 -1 response with Al(III) concentration is observed over the range of 1.0x10 to 1.0x10 mol L with a-9 -1 detection limit of 1.0x10 mol L . The relative standard deviation (n= 8) at a concentration level of-7 -11.0x10 mol L is 2.65%. The prepared electrode was successfully applied for the determination ofAl(III) in different real water samples. These samples were collected from the underground water ofTaif City. In order to investigate the reliability of the suggested electrode, the tested samples were alsodetermined by independent standard method using ICP-OES. The merits offered by the new electrodeincluding small size, simple construction, low cast, good accuracy and high precision.