Volume 38, Issue 3 (May 1993)
Spectroscopy of Rare Earth-Ruhemann's Purple Complexes
The complexes Ruhemann's Purples form with europium or terbium salts are suitable for fingerprint development on strongly fluorescent surfaces because they show enhancement of the lanthanide luminescence via intramolecular energy transfer and because the lifetime of the luminescence is much longer than that of the usual background fluorescence. They are therefore suitable for time-resolved luminescence imaging. The complexes are useful for fingerprint staining on smooth surfaces, since they are readily prepared in solution, as well as for fingerprint detection on porous surfaces, such as paper, where the procedure is similar to the by now routine ninhydrin/zinc chloride treatment, except that the nitrate or acetate are used in many instances, instead of the chloride, in the rare earth case, depending on paper type.