Colorimetric solid-phase extraction method for Cu(II) ion determination using 2-hydroxybenzaldehyde benzoylhydrazone as sensing reagent.

A new sensor based on the use of 2-hydroxybenzaldehyde benzoylhydrazone as a colorimetric reagent immobilized onto styrenedivinylbenzene disks has been carried out for the determination of Cu(II) ions within several minutes. The sensor is designed on a rapid and easy two-step procedure: (1) the extraction of Cu(II) ions onto a disk loaded with the copper-selective colorimetric reagent and (2) the determination of the complexed analyte directly on the surface of the disk using diffuse reflectance measurements at 400 nm. The color of the disk changed from white to green in the presence of Cu(II) ions.

Selective chemosensor for copper ions based on fluorescence quenching of a Schiff-base fluorophore.

A Schiff base-based fluorescent chemosensor has been studied for divalent copper detection. The formation of 2-hydroxybenzaldehyde benzoylhydrazone-Cu(2+) complex induced a fluorescence quenching of this compound in a medium of water/ethanol (53% v/v) and 0.05 M phosphate buffer (pH 7.