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 2.0 106
–3.1 103 M with detection
limit of 2.0 106 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 1 104
–2 103 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.
2011 El