Replacing Synperonic® N in the physical developer fingermark visualisation process: Pseudo-operational trial and parameter studies

Abstract

A reformulated physical developer (PD) solution has been devised to replace the use of Synperonic® N for environmental reasons. The performance of the replacement solution has proved promising in laboratory trials using planted fingermarks [1] however; this may not always represent how a reagent works on real world samples. This paper therefore explores the effectiveness of the decaethylene glycol monododecyl ether (DGME)-based PD formulation through a pseudo-operational trial. A range of naturally handled, porous substrates were processed, which totalled over 600 samples that had been previously treated with amino acid reagents (1,2-indandione (IND) or 1,8-diazafluoren-9-one (DFO) and ninhydrin). The trial was representative of the operational use of PD at the end of a processing sequence for porous exhibits. The results from the trial establish that DGME is an effective replacement detergent for Synperonic® N in PD solutions and demonstrated the added benefit of using PD as a sequential treatment. Planted mark studies to assess the parameters of the DGME-based PD formulation are also included in this paper. These studies explored the preparation, processing and storage temperature required for the solution as well as the shelf life. The effectiveness of DGME-based PD on items that have been previously wetted was also investigated. These studies show the formulation is suitable for use in an operational laboratory and is therefore an effective replacement formulation for the Synperonic® N-based PD.