A novel mixed matrix membrane of phenolphthalein hydrazide and polysulfone for the detection of copper ions in environmental water samples

The novel membrane test strip of phenolphthalein hydrazide (PH)‐polysulfone has been designed and demonstrated for Cu 2+ ions detection. Before finding performance of membrane the studies with PH alone has been performed. Aqueous solutions of PH are colorless, but upon interaction with Cu 2+ ions become pink (when 8.2 ≤ pH ≥ 12). The colorimetric change is initiated by the coordination of Cu 2+ with PH as a polydentate ligand, opening the spirolactam ring that subsequently hydrolyses releasing phenolphthalein (P). Further membrane was preloaded with PH that could be used as a simple, low cost, and portable sensor for Cu 2+ ions in environmental water samples. Given the detection limits of this sensor, a maximum response would warn the tester that Cu 2+ concentrations were above safe drinking regulation values. Approximate concentrations can be determined via a color comparison chart. Different metal ions were tested in order to determine the chemodosimeters specificity, of the 12 tested ions only Hg 2+ induced a similar molecular transformation (i.e., PH to P). The chemodosimeter allows the quantification of Cu 2+ ions in the linear dynamic range of 0–22 μM. The Sandell sensitivity, limit of detection, limit of quantification, and relative standard deviation were found to be 0.276 μg/mL/cm 2 , 0.279 μM, 1.674 μM, and 0.682% respectively. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019