A Schiff base chemical sensor for selective detection of hexavalent chromium ions: Real sample application

In this study, a straightforward Schiff base (2-(phenylmethyl-1-hydrazine formamide)) was synthesized via ionic liquid catalysis using benzaldehyde and aminourea hydrochloride. This approach represents a simple, efficient, and environmentally friendly synthesis method, with the added benefit of recyclability and reusability of the ionic liquid catalyst. Additionally, the Schiff base exhibits considerable capability for anion detection and demonstrates selective identification of CrO42-and Cr2O72-across different pH environments. The stoichiometric ratio was determined to be 2:1 through UV-vis absorption titration, with detection limits for CrO42-and Cr2O72-measured at 6 x 10-5 M and 7 x 10-5 M, respectively. To assess the probe's complexation mechanism with hexavalent chromium ions, infrared spectroscopy, and hydrogen nuclear magnetic resonance spectroscopy were employed.