Herein, we present reliable, robust, stable, and cost-effective solid-contact ion-selective electrodes (ISEs) for perchlorate determination. Single-walled carbon nanotubes (SWCNTs) were used as solid-contact material and indium (III) 5, 10, 15, 20-(tetraphenyl) porphyrin chloride (InIII-porph) as an ion carrier. The sensor exhibited an improved sensitivity towards ClO4- ions with anionic slope of -56.0 ± 1.1 (R2 = 0.9998) mV/decade over a linear range 1.07 × 10-6 - 1.0 × 10-2 M and detection limit of 1.8 × 10-7 M. The short-term potential stability and the double-layer capacitance were measured by chronopotentiometric and electrochemical impedance spectroscopy (EIS) measurements, respectively. The sensor is used for ClO4- determination in fireworks and propellant powders. The results fairly agree with data obtained by ion chromatography.
Keywords: SWCNTs; fireworks and propellants; indium-porphyrin; perchlorate; potentiometric sensors; solid-contact ISEs.