Use of tetracyanoplatinate (ii) for the luminescent detection of metalions

The tetracyanoplatinate(II) (TCP) ion forms insoluble fluorescent compounds with many metal ions. This property has not hitherto been exploited for analytical use. The soluble sodium TCP salt has been applied as a reagent for metal ion detection. Fluorescent precipitates useful for detection of the metal ions were obtained with Y(III), Zr(IV), Ag(I), Zn(II), Cd(II), Hg(I), Hg(II), A1(III), Pb(II), La(III) and Th(IV). Limits of detection ranged from 5 to 200 ppm. With ammonium acetate as a masking agent, selective detection of 10 ppm of silver was achieved in the presence of the other metal ions. As little as 20 ppm of zirconium can be detected in the presence of hafnium, which yields a non-fluorescent precipitate.