Anodic Stripping Voltammetric Determination of Lead(II) with a 2-Aminopyridinated-Silica Modified Carbon Paste Electrode

摘要

A carbon paste electrode modified with organically functionalized silica was used for the determination of lead.The measurements were carried out in three steps including an open circuit accumulation followed by electrolysis of accumulated lead at the carbon paste electrode and differential pulse voltammetric determination.The effects of several experimental variables such as carbon paste composition,pH and concentration of supporting electrolyte,electrolysis potential,and electrolysis time were studied.The resulting electrode demonstrates linear response over a wide range of Pb(II) concentration (5-1000 ng mL_1) with an accumulation time of 60 sec.The effects of potential interfering ions were studied,and it was found that the proposed procedure is free from most interferences.Long lifetime and rapid and convenient renewal of electrode surface allows the use of a single modified electrode surface in multiple analytical determinations over at least 4 months.The prepared electrode was used for determination of lead spiked in a hair sample,and very good recovery results were obtained over a wide concentration range of lead.