Highly sensitive determination of zinc(II) in dietary supplements using a potentiometric sensor based on benperidol as an ionophore

A highly sensitive potentiometric sensor was developed for the determination of Zn(II) in dietary supplements using benperidol (BD) as a neutral ionophore. A coated graphite electrode was fabricated with a PVC-based membrane containing BD, sodium tetraphenylborate as an ionic additive, and nitrobenzene as a plasticizer. The membrane composition was optimized to achieve the best potentiometric performance. Under optimum conditions, the sensor exhibited a near-Nernstian slope of ۳۰.۶ ± ۰.۲ mV decade⁻¹ over a wide linear concentration range of ۱.۰ × ۱۰⁻⁷ to ۱.۰ × ۱۰⁻¹ mol L⁻¹, with a detection limit of ۸.۵ × ۱۰⁻⁸ mol L⁻¹ and a correlation coefficient of ۰.۹۹۹۸. The electrode showed a stable potential response over the pH range of ۳.۰–۸.۰ and maintained satisfactory potentiometric behavior in solutions containing up to ۲۰% organic solvents. The response time was approximately ۱۰ s, while the electrode retained near-Nernstian performance for up to ۱۶ weeks. The sensor demonstrated high selectivity toward Zn(II) over the investigated interfering ions, with selectivity coefficients indicating ۱۰۰–۱۰,۰۰۰-fold preference for Zn(II). The proposed electrode was also successfully applied to the potentiometric titration of Zn(II) with EDTA and to the determination of Zn(II) in four dietary supplement samples, giving recoveries between ۹۵.۰% and ۱۰۲.۰%. These results demonstrate that the developed benperidol-based potentiometric sensor provides a sensitive, selective, rapid, and practical method for Zn(II) determination in dietary supplements.

کلیدواژه ها:

Zinc(II) ، Benperidol ، Ion selective electrode ، Potentiometric sensor ، Dietary supplements