A novel citrate selective electrode based on surfactant modified nano-clinoptilolite

A citrate-selective sensor was prepared by modification of a PVC membrane with modified nano-clinoptilolite particles by hexadecyltrimethyl ammonium surfactant (SMZ). A Nernstian slope of 29.9 ± 0.2 mV per decade of citrate concentration was obtained over the concentration range of 5.0 × 10−5–5.0 × 10−2 mol L−1 of citrate. The electrode showed a fast response time (⩽10 s) and a detection limit of 1.3 × 10–5 mol L−1 of citrate. The linear range and detection limit were respectively changed to 1.0 × 10−4–5.0 × 10−2 mol L−1 and 1.0 × 10−4 mol L−1 of citrate when the micronized clinoptilolite particles were used.