Reusable anion detection kit: An aqueous medium anion detection

Test paper coated with reduced Schiff base 1, can selectively detect fluoride and acetate ions in aqueous medium. With such a drastic color change, detection can be achieved by just using the naked-eye, unaided by any optical instrument. Interestingly, the test paper can be re-used several times after washing with 3% HCl and distilled water respectively.