Diamond paste based electrodes for the determination of Pb(II) at trace concentration levels

Three types of monocrystalline diamond: natural diamond 1 μm, synthetic diamond 50 μm (synthetic-1), and synthetic diamond 1 μm (synthetic-2) were used for electrodes’ construction. The linear concentration ranges recorded for Pb(II), when natural diamond, synthetic-1 and synthetic-2 based electrodes were used were between 10⁻⁹ and 10⁻⁶; 10⁻¹⁰ and 10⁻⁷; and between 10⁻¹⁰ and 10⁻⁸ mol l⁻¹, respectively. Low detection limits which lie between 10 and 100 pmol l⁻¹ proves the sensitivity of the electrodes. It was found that Pb(II) yielded a peak at about +0.3±0.02 V (versus Ag/AgCl) for all the electrodes. Lead was determine with high reliability from water and tea samples at trace concentration levels using the proposed diamond paste based electrodes.