RESUMO
A study into the modification of 1,8-diazafluoren-9-one (DFO) formulations by the additions of metal salts into the working solution is reported. Similar additions have been found to increase the fluorescence of marks developed using other amino acid reagents including 1,2-indandione and the ninhydrin analogue 5-methylthioninhydrin. It was found that adding zinc chloride to give a 1:1 ratio of zinc ions:DFO molecules gave optimum fluorescence, and improvements in performance over the standard DFO formulation were achieved. Attempts to produce equivalent formulations with iron, nickel and palladium chlorides were unsuccessful. In a comparative trial with a 1,2-indandione-zinc formulation on brown paper and cardboard substrates, 1,2-indandione-zinc gave superior results and it was decided to focus further research on this reagent instead of DFO-zinc.
Assuntos
Compostos Aza , Dermatoglifia , Fluorescência , Indanos , Metais/química , Sais/química , Cloretos/química , Humanos , Indicadores e Reagentes/química , Ninidrina/química , Projetos Piloto , Compostos de Zinco/químicaRESUMO
This paper contains details of work carried out to examine the composition of 1,2-indandione formulations and to develop the most effective 1,2-indandione/zinc formulation for use under UK conditions. Previous research into the reactions of 1,2-indandione without zinc ions have concluded that formulations containing methanol produce stable hemiketals, which are less reactive to amino acids, resulting in reduced fluorescence intensity of developed fingermarks. In this study, fingermarks were treated using varying formulations of 1,2-indandione, with and without the presence of methanol and zinc ions. It was found that both were beneficial in producing marks of the highest fluorescence intensity, although too much methanol could have a detrimental effect on the quality the mark due to diffusion of ridge detail. Therefore the 1,2-indandione formulation recommended for further trials has been modified to contain both zinc ions and methanol.
