The Effect of Zinc Chloride, Humidity and the Substrate on the Reaction of 1,2-Indanedione-Zinc with Amino Acids in Latent Fingermark Secretions

Xanthe Spindler, Ronald Shimmon, Claude Roux, Christopher Lennard

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Anecdotal evidence from forensic practitioners and studies conducted under controlled conditions have indicated that the reaction between 1,2-indanedione and the amino acids present in latent fingermark deposits is highly susceptible to ambient humidity. The addition of catalytic amounts of zinc chloride to the 1,2-indanedione working solution – usually in the order of 1:25 to 1:4 molar ratio (indanedione:zinc) – significantly improves the colour and luminescence of fingermarks treated under dry conditions but appears to have a negligible effect on fingermarks treated in humid environments. The results presented in this paper confirmed that zinc(II) ions added to the 1,2-indanedione working solution act as a Lewis acid catalyst, stabilising a key intermediate during a rate-limiting hydrolysis step. Furthermore, studying the reaction using a chromatography-grade cellulose substrate method previously reported confirmed that cellulose substrates play a major role in facilitating the indanedione-amino acid reaction by acting as a surface catalyst in the early stages of the reaction and by directing the formation of the desired luminescent product (Joullié’s Pink)
Original languageEnglish
Pages (from-to)150-157
Number of pages8
JournalForensic Science International
Volume212
Issue number1-3
Publication statusPublished - 2011

Fingerprint Dive into the research topics of 'The Effect of Zinc Chloride, Humidity and the Substrate on the Reaction of 1,2-Indanedione-Zinc with Amino Acids in Latent Fingermark Secretions'. Together they form a unique fingerprint.

Cite this