Application of surfactant modified zeolite carbon paste electrode (SMZ-CPE) towards potentiometric determination of sulfate

A sulfate-selective electrode based on surfactant modified zeolite (SMZ) particles into carbon paste has been proposed (SMZ-CPE). The electrode was fully characterized in terms of composition, response time, ionic strength range, thermal stability and usable pH range. The electrode containing 10% of the SMZ was exhibited linear response range to sulfate species in the range of 2.0 × 10−6–3.1 × 10−3 M with detection limit of 2.0 × 10−6 M and Nernstian slope of 29.8 ± 0.8 mV per decade of sulfate concentration. The electrode response remains constant in the pH range of 4–10 and in the presence of 1 × 10−4–2 × 10−3 M NaNO3. The response of the electrode reaches equilibrium within several second after immersing the electrode in sulfate solution. A successful application of sulfate determination sulfate in real sample of a pharmaceutical zinc sulfate capsule, using direct potentiometry, is presented. The electrode was also used for potentiometric titration of sulfate. The validation of the obtained results in each case was proved by statistical methods.

A sulfate-selective electrode based on surfactant modified zeolite (SMZ) particles into carbon paste has been proposed (SMZ-CPE). The electrode was exhibited linear response range to sulfate in the range of 2.0 × 10−6–3.1 × 10−3 M with detection limit of 2.0 × 10−6 M and Nernstian slope of 29.8 ± 0.8 mV per decade of sulfate concentration. The successful determination of sulfate in real sample of a pharmaceutical zinc sulfate capsule, using direct potentiometry and potentiometric titration are presented.Figure optionsDownload as PowerPoint slideHighlights
► Surfactant modified zeolite in carbon paste electrode can response to anions.
► The obtained SMZ-CP electrode showed a Nernstian response to sulfate in the used conditions.
► The proposed method cab be used in direct and indirect potentiometry and real samples.