Tuschenanalyse im P 11702

Near-infrared reflectography and imaging X-ray fluorescence analysis reveal that carbon inks of two different compositions were used in the papyrus manuscript Berlin P 11702. In contrast with the writing ink, one of the carbon drawing inks contained a significant addition of iron. This result emphasizes the need for routine instrumental ink analysis.

Ink Classification in Hyperspectral Images

Hyperspectral imaging provides vital information about the objects and elements present inside the image. That’s why they are very useful in satellite imagery as well as image forensics. Hyperspectral document analysis (HSDI) can be used for document authentication using ink analysis which can provide sufficient information about the composition and type of ink. In this project, we have implemented HSDI based ink classification technique using Principle Component Analysis for dimensionality reduction and K-means clustering for ink classification. This is unsupervised learning approach and it is very simple and efficient in order to classify limited number of bands. We have used this technique to classify 33 different bands of ink.

Forensic Analysis of Commercial Inks by Laser-Induced Breakdown Spectroscopy (LIBS)

Laser-induced breakdown spectroscopy (LIBS) was tested for all of the relevant issues in forensic examinations of commercial inks, including classification of pen inks on one paper type and on different paper types, determination of the deposition order of layered inks, and analysis of signatures and toners on one questioned document. The scope of this work was to determine the potential of a single LIBS setup that is compatible with portable instruments for different types of ink analysis, rather than building a very large database for inks and papers. We identified up to seven metals characteristic for the examined inks, which allowed to fully discriminate all eight black inks on one type of printing paper. When the inks were tested on ten different papers, the correct classification rates for some of them were reduced for reasons thoroughly studied and explained. The replicated tests on three crossing points, each one involving a pair of blue or black inks, were successful in five cases out of six. In the test simulating documents of forensic interest (questioned documents), LIBS was able to correctly identify the differences in three inks used for signatures on one of the three pages and the use of different printing inks on each page of the document.

Examination of Different Inks Available in Ethiopia Using VSC 8000, U.V-Visible Spectrophotometer and TLC: Study of Their Discrimination Potential

Ink analysis is the most challenging and commonly encountered problem faced by a forensic chemist. Ink present on documents such as contracts, cheques, testaments, medical records, to quote just a few, is regularly contested for its authentication. In this paper, we have examined the various inks available in Ethiopia (speciallyArba Minch) using chromatography and spectroscopy methods, and have tried to decode the chemical compositions of these inks emphasizing on coloring agents followed by evaluating the discrimination potential of these techniques. This study is the first kind of detailed examination of inks available in Ethiopia as there is no precedence literature to it. It was found out that the examined ink samples can be divided into five major groups having mainly rhodamine b, rhodamine 6G and crystal violet as coloring agents. The TLC and UV-Vis techniques although discriminate inks samples to a little better extent than VSC, but VSC should be preferred due to its non-destructive nature.