An alternative carrier solvent for fingermark enhancement reagents

Abstract

Solstice Performance Fluid (PF), trans-1-chloro-3,3,3-trifluoropropene, is presented as an alternative to HFE7100, methoxy-nonafluorobutane, as a carrier solvent in a number of chemical formulations used for the visualisation of latent fingermarks. The supply of HFE7100 may be at risk due to a recent European Union regulation to control global warming. Laboratory trials using split depletions and a pseudo-operational trial of 1000 porous samples have shown that Solstice PF is a viable alternative to HFE7100 for the chemical formulations of ninhydrin and 1,2-indanedione. Other preliminary trials have also indicated that Solstice PF can be used as a carrier solvent for the zinc toning of marks found using ninhydrin as well as the α-naphtholflavone fixative solution for iodine developed marks. Results from the pseudo-operational trial demonstrate that the number of marks detected by ninhydrin and 1,2-indanedione formulations for each carrier solvent is comparable. When compared to HFE7100, advantages of Solstice PF include a very low global warming potential and atmospheric lifetime in addition to a higher wetting index and lower costs. This study also provides a validation study that supports the potential replacement of DFO with 1,2-indanedione.

Fingermark visualisation with iron oxide powder suspension: The variable effectiveness of iron (II/III) oxide powders, and Tween® 20 as an alternative to Triton™ X-100

“…Examples include the reformulation of ninhydrin working solution [17][18][19] due to the CFC bans in the mid 1990's [18]; the replacement of Synperonic N surfactant with Tween ® 20 in the U.S. Secret Service physical developer formulation [20,21] due to the phase-out of nonylphenol ethoxylates [20]; and the development of a less-flammable methoxypropanol-based solvent black 3 formulation for use at crime scenes [22,23]. Recent work includes replacing HFE formulations for amino acid reagents [24].…”

Effect of carrier solvent in 1,2-indanedione formulation on the development of fingermarks on porous substrates

“…A major research project which recommended the use of HFE7100 as an alternative carrier solvent to Freon in formulations for latent fingermark detection was carried out by Gardner and Hewlett [7] in 2003. However, HFE7100 still has the disadvantages of environmental pollution and high cost though it is relatively safe and effective [21] . HFE7100 is also currently under a consideration ban within the EU [22] .…”

The optimisation of fingermark enhancement by VMD and Lumicyano™ on thermal paper

“…This process is successful at enhancing marks; however, the stripping of the thermal layer removes text, causes any written evidence on the paper to be lost and if the article is not processed in acetone long enough to fully remove the thermosensitive layer, blackening can still occur [5,9]. Additionally, the carrier solvent HFE7100, frequently used in these processes is relatively expensive (£85.33 per litre as of 2017), has a high Global Warming Potential (GWP), and the shelf-life of the prepared solution is approximately only 1 week [4,[10][11][12][13]. These problems also occur with the acid-free indanedione standard method employed by the Autralian Federal Police (AFP) for thermal paper.…”