The effect of zinc chloride, humidity and the substrate on the reaction of 1,2-indanedione–zinc with amino acids in latent fingermark secretions

Use of Squid as an Alternative to Human Skin for Studying the Development of Hit Marks on Clothes

“…It has been stated that the reaction between amino acids and 1,2-IND/Zn is catalyzed by cellulose [15]. Cellulose is the major component of cotton, and a starting material for making rayon [16,17].…”

Visualising substrate–fingermark interactions: Solid-state NMR spectroscopy of amino acid reagent development on cellulose substrates

“…1) -are typically limited to visible absorption and luminescence microspectrophotometry in situ on cellulose substrates [1][2][3]. Further structural information is often revealed using traditional solutionbased analytical techniques such as electrospray ionisation mass spectrometry, liquid nuclear magnetic resonance (NMR) spectroscopy or Fourier transform infrared spectroscopy (FTIR) [4][5][6][7][8][9][10].…”

“…Proton migration in DFOY caused by residual methanol was also identified by Wilkinson to cause significant broadening across all regions of the 1 H NMR spectrum in deuterated chloroform [4]. As yet, no published studies exist on the structural elucidation of the Forensic Science International 250 (2015) [8][9][10][11][12][13][14][15][16] Most spectroscopic studies of the reaction products formed by ninhydrin, 1,2-indanedione-zinc (IndZn) and 1,8-diazafluoren-9-one (DFO) when reacted with amino acids or latent fingermarks on paper substrates are focused on visible absorption or luminescence spectroscopy. In addition, structural elucidation studies are typically limited to solution-based mass spectrometry or liquid nuclear magnetic resonance (NMR) spectroscopy, which does not provide an accurate representation of the fingermark development process on common paper substrates.…”

“…Although solution-based techniques such as liquid NMR spectroscopy can provide important information on chemical structure, the study of fingermark reagents in solution does not provide an accurate account of the interactions between the paper substrate and fingermark reagents such as indanedione-zinc [10]. Consequently, an approach that permits the study of these reagents and their reaction products in situ is required to advance our understanding of fingermark detection on these complex matrices.…”

“…The results of our previous study indicated that 13 C-MAS-NMR was a suitable method for characterising the formation of JP (extracted under controlled conditions) with four common amino acids [10]. The aim of the research presented in this paper was to investigate whether 13 C-MAS-NMR could provide a simple and effective method for studying solvent-sensitive amino acid reaction products (resulting from the application of fingermark detection reagents) in situ on cellulose substrates.…”