الفهرس 
English CoverOnly 14 pages are availabe for public view
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Abstract
Forensic examiners are overwhelmed every day by many cases of official and other business documental forgery. Many cases of which involve the addition or deletion of one or more similar writing/copying paper(s) to the original document. Another challenge that faces the examiners is the determination of the intersected signature lines chronological sequence. This suggests a forgery case in that instance if such modifications are made without the consent of all parties. The importance of the documents under question mandates the usage of non-destructive discriminative analytical methods. The main tool used by the forensic examiners in the Egyptian medicine forensic authority is the Video spectral comparator (VSC). However, many times the latter doesn’t give conclusive suggestions to the expert who becomes hesitant to give a fair judgment of the case. The current study investigated the use of a molecular spectroscopic technique like Fourier transform infrared spectroscopy (FTIR) as a non-destructive technique in the discrimination between writing/copying papers and the sequence of the used writing inks by Atomic force microscopy (AFM). The similar used papers were from the Egyptian market and commonly used in documents under question. We have examined in the current investigation twelve different (Copy/writing) paper sheets from the main paper sources found in the Egyptian market with VSC, ATR FTIR and chemometric analysis. The VSC device that is currently used by the Egyptian medicine forensic authority has limited capabilities in distinguishing different paper sheets according to their sources. It is solely dependent on the judgment of the expert’s eyes creates a challenging situation with the lack of numeric spectra display of the obtained images. ATR FTIR is a promising analytical tool. that assist forensic documents examiners in their uphold cases with different documents as it is a non-destructive technique, fast and needs no sample preparations [1]. It could as well identify the variable deformations in the spectral functional groups of cellulose. Yet, the available FTIR spectrometer with the available filters couldn’t give 100% confidence results in the discrimination between the twelve paper sheets. This is due to the overlapping of the broad bands of many functional groups. In this study, we could precisely determine the chronological sequence between different ink pens and laser toners by the combining use ATR-FTIR spectroscopy and laser scanning microscopy represented by AFM to construct 3D topography images for such intersecting lines. The multivariate analysis represented by PCA chemometrics with the use of the chemical qualitative characteristics of the documents could be of much better help to the forensic documents examiners in their characterization investigation of different papers and documents. Based on the principal components of paper manufacturing which are cellulose, inorganic fillers and other bleaching additives. We had a better discrimination capacity upon adopting the spectral range of 830-1185 cm-1 than that of 1186-1800 cm-1. As by the former, we could cluster the paper sheets that are without ECF from those that are with ECF pulps. We could as well distinguish papers with different inorganic fillers concentrations and different cellulose nature. The combined results of the VSC, ATR-FTIR and chemometric analysis could be of a major importance to solve real fraud causes to challenge the authenticity of contracts and/or agreements.