title: Latent Fingerprint Development on Thermal Paper Using Traditional Ninhydrin and 1,2-indanedione.
abstract: Thermal paper poses a significant challenge to latent print development as it tends to change color when traditional fingerprint development formulations are applied to it. In this study, the optimal components of ninhydrin, 1,2-indanedione, 1,8-diazafluoren-9-one (DFO), and 5-methylthioninhydrin (5-MTN) for yielding clear fingerprints on thermal paper were determined by systematically adjusting the relative amounts of the reagents, polar solvents, and the nonpolar diluent petroleum ether, followed by validation on text-printed thermal paper. Specifically, 3.0% ethyl acetate as the polar solvent in petroleum ether was found to be the optimal combination; the optimal dilution ratios of ninhydrin, DFO, and 5-MTN original solutions with petroleum ether were 1 to 2, 11, and 7, respectively. The optimal concentration of 1,2-indanedione in petroleum ether was 0.125 g/L, with a string of 0.5% ethyl acetate in petroleum ether.
authors.affiliation: Forensic Science Section, Changhua County Police Bureau, 778, Sec. 2, Jhong-jheng Rd., Changhua City, 50004, Taiwan.|Department of Forensic Science, Central Police University, 56, Shu-Jen Road, Kwei-San, Taoyuan, 33304, Taiwan.
authors.forename: Chun-Chieh
authors.identifier: http://orcid.org/0000-0002-0362-2396
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Forensic Science Center, Criminal Investigation Bureau, 5, Lane 553, Chung Hsiao East Road Section 4, Xin Yi area, Taipei, 10675, Taiwan.
authors.forename: Yung-Chien
authors.initials: YC
authors.lastname: Yu
authors.affiliation: Henry C. Lee Institute of Forensic Science, University of New Haven, 300 Boston Post Road, West Haven, CT, 06516.
authors.forename: Henry C
authors.initials: HC
authors.lastname: Lee
authors.affiliation: Department of Forensic Science, Central Police University, 56, Shu-Jen Road, Kwei-San, Taoyuan, 33304, Taiwan.
authors.forename: Yun-Seng
authors.initials: YS
authors.lastname: Giang
authors.affiliation: Department of Forensic Science, Central Police University, 56, Shu-Jen Road, Kwei-San, Taoyuan, 33304, Taiwan.
authors.forename: Sheng-Meng
authors.initials: SM
authors.lastname: Wang
keywords: 1,2-indanedione; 1,8-diazafluoren-9-one; 5-methylthioninhydrin; fingerprint; forensic science; latent print; ninhydrin; thermal paper