Separation of Latent Fingermark Residue by Thin-Layer Chromatography

A method for the separation of the lipid and nitrogeneous constituents of latent fingermarks using thin-layer chromatography (TLC) is described. The lipid partition is separated into bands corresponding to fatty acids, cholesterol, squalene, and triglyceride controls. Observation of developed plates using ultraviolet fluorescence detection in the region 310–390 nm has determined that the major fluorescent material is lipid in nature and runs with the squalene control band. After running, the TLC plates were treated with the following latent fingermark enhancement procedures: visible fluorescence, ninhydrin, 1,8-diazafluoren-9-one and physical developer. The technique provides an approach to understanding the chemical and photoluminescent processes of latent fingermark enhancement.