Development and surface characterization of a bis(aminotriazoles) derivative based renewable carbon paste electrode for selective potentiometric determination of Cr(III) ion in real water samples

Abstract

Regarding the Cr(III) importance in the industrial, environmental, and even biological systems, development of highly selective and sensitive Cr(III) sensor is a challenge. In this work, a new carbon paste electrochemical sensor containing a synthesized bis(aminotriazoles) derivative namely 1,3-bis[4-amino-5-benzyl-1,2,4-triazol-3-ylsulfanyl]propane (BABTSP) as the Cr(III) selective ionophore was described. Factors affecting sensor’s response were studied and optimized. The proposed sensor exhibited a Nernstian slope of 20.05 ± 0.35 mV decade−1 covering broad linear range of 1.0 × 10−8−5.0 × 10−2 mol L−1 and detection limit was 8.0 × 10−9 mol L−1 for 3 months over pH range of (2.3–5.2) and fast response time (<10 s). The proposed sensor was selective for Cr(III) ions that was confirmed by separate solution method (SSM) and fixed interference method (FIM) . The sensor was precise and reproducible (RSD% range = 0.8–2.45) and effectively used in potentiometric titration of Cr(III) against EDTA and in diverse water samples analysis with recovery data of 96.08–100.2%. The lipophilicity of the applied ionophore was investigated through contact angle measurement technique and average contact angle was 127.59° that resulted in sensor’s mechanical stability. To study the response mechanism and morphology of the prepared sensor, scanning electron microscope (SEM), energy dispersive X-ray (EDX) and FT-IR spectroscopy were used.