Tuned galvanostatic polarization of solid-state lead-selective electrodes for lowering of the detection limit

Lowering of the detection limit of solid-state lead-selective electrodes was achieved by using the tuned galvanostatic polarization method. A Nernstian response was obtained down to nanomolar concentrations (low detection limit 10−9 mol dm−3 Pb2+). Good repeatability of the calibration curves was achieved by using a well established measuring procedure. Relatively high cathodic current densities were applied to the solid-state membrane in order to shorten the measurement time. Successful determination of lead in a synthetic sample (pPb2+ = 7.97 ± 0.08) was achieved by introducing an analytical protocol and favourably compared to inductively coupled plasma mass spectrometry (pPb = 7.93). By applying this method, a significant improvement in the detection limit of solid-state lead-selective electrodes was attained.

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► We use lead (II) sensitive ion-selective electrode with solid-state membrane.
► We apply electrical current to enhance the electrode measuring range with a linear response.
► The current applied allows to hinder parasitic release of Pb(II) ions from the ion-selective membrane.
► The procedure proposed allows to measure ultra-low concentrations of lead ion.