Stojkovikj, Sasho and Oklevski, Slobodan and Jasuja, Om Prakash and Najdoski, Metodija (2019) Design of a Novel Nitrogen Dioxide Method for Visualization of Latent Fingerprints on Thermal Paper. In: 3rd World Conference and Exhibition on Forensic Science, 3-4 June 2019, Berlin, Germany.
![[thumbnail of Abstract]](/style/images/fileicons/text.png) |
Text (Abstract)
Abstract 2.pdf Download (333kB) |
|
Text (Book of Abstracts and Programme)
Forensic Science-Book of Abstracts.pdf Download (3MB) |
Abstract
Thermal paper is widely used for printing bills, ATM slips, invoices, receipts, tickets and etc. Actually, this material presents a paper which is one-side coated with thin layer (i.e thermal layer) that contains leuco dyes, developers, and solvents with low melting point (45-65 °C). The printing process on this kind of paper is achieved by applying heat on its surface that leads to slight melting of the solid solvent which allows contact between the components from the thermal layer thus inducing color change.
A new chemical method for visualization of latent fingerprints on thermal paper based on treatment with nitrogen dioxide (NO2) gas is presented in this work. The gas is generated by reaction between zinc and diluted nitric acid in a simple chamber. The proposed method does not require fingerprint’s fixation reagent (post-treatment) i.e. the fingerprint remain permanent for more than one week, without any changes in its quality. The general visualization mechanism is based on providing acidic conditions in order to induce tautomeric transformation of the leuco dye’s molecules in the thermal layer, accompanied with color change of the papillary lines through the completely impressed fingerprint. This method provides more than satisfactory contrast between the visualized fingerprints and the background surface. The visualized fingerprints are qualified with high clarity and continuity of the friction ridges, and also clarity of the second level characteristics and third level features. The method was evaluated by dactyloscopic analysis and according to the results, it can be exemplified with high identification capacity.
| Item Type: | Conference or Workshop Item (Speech) |
|---|---|
| Subjects: | Natural sciences > Chemical sciences Natural sciences > Other natural sciences |
| Divisions: | Faculty of Technology |
| Depositing User: | Saso Stojkovik |
| Date Deposited: | 04 Mar 2024 13:24 |
| Last Modified: | 05 Mar 2024 11:33 |
| URI: | https://eprints.ugd.edu.mk/id/eprint/33812 |
Actions (login required)
 |
View Item |