title: Evaluation and comparison of 1,2-indanedione and 1,8-diazafluoren-9-one solutions for the enhancement of latent fingerprints on porous surfaces.
abstract: 1,2-indanedione (1,2-IND) and 1,8-diazafluoren-9-one (DFO) are used in the forensic field to enhance latent fingerprints deposited on porous surfaces due to the formation of fluorescent products by reacting with the amino acids present in the papillary exudate. The study was carried out in collaboration with the Fingerprints and Photography Section of the Carabinieri Scientific Investigation Department (RIS) of Rome, in which laboratories, until now, DFO has been the most used because of its excellent enhancing properties, even if it is more expensive and relatively toxic in comparison with the 1,2-IND. The aim of this work was then to evaluate and to compare the effectiveness of three solutions of 1,2-IND in different formulations and a DFO solution employed as single enhancing treatments, in order to assess whether it was possible to replace a reagent with the other obtaining equally satisfying results. In this case, white office paper was selected as deposit surface since it also permitted one to observe those reaction products that appear visible to a naked eye. Beside to a qualitative study of the visual characteristic of the enhanced fingerprints, further quantitative studies were conducted on the intensity of fluorescence of the products and on the consumption of amino acids during the reaction. The analyses, which at first were conducted on standard samples, were then repeated on real samples to validate the results obtained. The DFO confirmed its excellent enhancement properties, but also one of the three solutions of 1,2-IND showed comparable properties in terms of enhanced fingerprint definition and stability over time from the completion of a crime. As a result, we proved that a selected 1,2-IND formulation may replace with satisfactory achievements the DFO solution currently employed, providing also advantages from the point of view of safety and cost savings.
authors.affiliation: Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, University of Alcalá, Ctra. Madrid-Barcelona Km. 33.6, 28871 Alcalá de Henares, Madrid, Spain; University Institute of Research in Police Sciences (IUICP), University of Alcalá, Alcalá de Henares, Madrid, Spain. Electronic address: valentina.d@uah.es.
authors.forename: Valentina
authors.initials: V
authors.lastname: D'Elia
authors.affiliation: Department of Chemistry, University of Rome "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Materazzi
authors.affiliation: Sezione di Impronte e Dattiloscopia, Reparto Carabinieri Investigazioni Scientifiche, 00191 Rome, Italy.
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Iuliano
authors.affiliation: Sezione di Impronte e Dattiloscopia, Reparto Carabinieri Investigazioni Scientifiche, 00191 Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Niola
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D003878:Dermatoglyphics; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007189:Indans / Q000737:chemistry*; D008027:Light; D010209:Paper; D016062:Porosity; D013499:Surface Properties
chemical_list: C413384:1,2-indanedione; C406982:1,8-diazafluoren-one; D001372:Aza Compounds; D007189:Indans
keywords: 1,2-indanedione; 1,8-diazafluoren-9-one; IND–Zn; Latent fingerprints; Porous surfaces