Determination of Aluminium by Potentiometry Using Carbon Paste Ion Selective Electrode Based on N,N'-bis(salicylidene)-1,3-Propanediamine Ligand

A new Al3+ carbon paste ion selective electrode based on N,N'-bis(salicylidene)-1,3-propanediamine (SB-Salpr) was prepared for the quantification of trace Aluminum. The proposed sensor has significant selectivity and sensitivity toward Al3+ ions in the presence of a wide range of cations including alkaline, alkaline earth, intermediate and heavy metal ions. The use of multi-walled carbon nanotubes (MWCNTs) and nanosilica in the composition of carbon paste sensors caused improvements in their characteristics; these materials have suitable conductivity and can help in conducting signals through the carbon paste sensors. The electrode consisted of 3% of MWCNTs, 0.5% of nanosilica, 25% of paraffin oil, 66.5% of graphite powder and 5% of SB-Salpr ligand. The sensor shows a Nernstian response to Al3+ ions with a Nernstian gradient of 20.2 +/- 0.1 in the concentration range of 1.0 x 10(-6) to 1.0 x 10(-2) M with the detection limit of 2.1 x 10(-7) M. The sensor response is independent of pH in the range of 24 and possesses the advantages of fast response time less than 5 s. According to the obtained results, Al3+ nanocomposite carbon paste sensor exhibited good selectivity in the presence of a few metal ions. The sensor was effectively used as an indicator electrode in the potentiometric titration of Al3+ ions with ethylenediaminetetraacetic acid.

Automated summary

A new Al3+ carbon paste ion selective electrode based on SB-Salpr was developed with significant selectivity and sensitivity toward Al3+ ions, showing potential for trace aluminum quantification.