A validation study of the 1,2-indandione reagent for operational use in the UK: Part 1 - Formulation optimization.

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.

A validation study of the 1,2-indandione reagent for operational use in the UK: Part 3-Laboratory comparison and pseudo-operational trials on porous items.

Laboratory trials, followed by a comparative pseudo-operational trial of a 1,2-indandione/zinc formulation and 1,8-diazafluoren-9-one (DFO) was carried out on a range of realistically-handled papers, card and cardboard. In laboratory trials over 7500 split marks were assessed and in the pseudo-operational trial in excess of 400 samples were treated with each of these processes before all the samples were then treated with ninhydrin. The results presented from both stages of the trials establish that 1,2-indandione was the most effective single process and that 1,2-indanedione followed by ninhydrin the most effective process sequence, with ninhydrin developing a significant number of new marks after 1,2-indandione.

A validation study of the 1,2-indandione reagent for operational use in the UK: Part 2 - Optimization of processing conditions.

This paper contains details of work carried out to identify the most effective processing conditions for the optimized 1,2-indandione/zn formulation developed for use under UK conditions. Using direct measurements of fluorescence taken from test spots of amino acids and eccrine sweat during oven processing, complemented with experiments on real fingermarks, it was established that processing temperatures above 120°C in the oven were detrimental to the fluorescence of the developed mark. Alternative methods of development to oven processing were found to be effective, but less controllable.

Fingermark visualisation on uncirculated £5 (Bank of England) polymer notes: Initial process comparison studies.

Experiments were conducted to investigate the effectiveness of a range of fingermark visualisation processes on brand new, uncirculated, £5 polymer banknotes (and their test note predecessors), as produced by the Bank of England (BoE). In the main study of this paper, a total of 14 individual processes were investigated on BoE £5 polymer banknotes, which included both 'Category A' processes (as recommended in the Home Office Fingermark Visualisation Manual) as well as recently developed processes, including fpNatural 2 powder (cuprorivaite) from Foster+Freeman and a vacuum metal deposition sequence that evaporates silver followed by zinc. Results from this preliminary investigation indicate that fpNatural 2, multimetal deposition, Wet Powder Black, iron oxide powder suspension and black magnetic powder are the most effective processes on these uncirculated £5 BoE polymer banknotes, when viewed under "primary viewing" conditions (white light or fluorescence).