Study of a Novel Bisnaphthalimidopropyl Polyamine as Electroactive Material for Perchlorate‐selective Potentiometric Sensors

In this work, the new polyamine bisnaphthalimidopropyl‐4,4’‐diaminodiphenylmethane is proposed as a new ionophore for perchlorate potentiometric sensors. The optimal formulation for the membrane comprised of 12 mmol kg^?1 of the ionophore, and 68 % (w/w) of 2‐nitrophenyl phenyl ether as plasticizer and 31 % (w/w) of high molecular weight PVC. The sensors were soaked in water for a week to allow leakage of anionic impurities and for one day in a perchlorate solution (10^?4 mol L^?1) to improve reproducibility due to its first usage. The stability constant for the ionophore‐perchlorate association in the membrane, log β_IL1=3.18±0.04, ensured a performance characterized by the slope of 54.1 (±0.7) mV dec^?1 to perchlorate solutions with concentrations between 1.24×10^?7 and 1.00×10^?3 mol L^?1. The sensors are insensitive to pH between 3.5 to 11.0, they have a practical detection limit of 7.66 (±0.42) ×10^?8 mol L^?1 and a response time below 60 s for solutions with perchlorate concentrations above 5×10^?6 mol L^?1. The accuracy of the results was confirmed by the analysis of the contaminant in a certified reference water sample.