ResourceSpectroscopy
Micro-Raman Study of the Sequence of Non-Intersecting Lines for Forged Document Investigation
14 Nov 2014In connection with investigation of fraud, counterfeiting, blackmail and anonymous letter cases, forensic experts frequently have to find out whether a document was altered after signing. In these cases the sequence of crossing printer and pen ink line often needs to be determined in order to resolve whether any of the printed text was printed after the signature. When there are no intersecting lines between the printed text and the pen ink lines, standard techniques used for sequencing are not applicable. This note demonstrates the application of micro-Raman spectroscopy to investigate the chronological sequence of printed and hand-written features on the documents even if there are no intersecting lines.
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Near Infrared SpectroscopyNear-infrared (NIR) spectroscopy measures the interaction of near-infrared light with a sample, including transmission, reflectance and absorbance, facilitating the identification of analytes. Measurements can be conducted using a Fourier-transform near infrared (FT-NIR) spectrometer, while there are also UV-Vis- NIR spectrophotometers that measure a broader spectrum of wavelengths. Find the best NIR spectroscopy products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Raman SpectroscopyRaman spectroscopy is used to discern the vibrational and rotational states of molecules and hence the chemical composition of a sample by measuring the inelastic scattering of monochromatic light. Explore a range of Raman spectrometers, including handheld/portable Raman spectrometers for QC/QA labs and in situ spectrometers for processes. Conduct Raman imaging for microanalysis of mixed samples using a Raman microscope. Raman spectrographs are also available. Find the best Raman spectroscopy products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.UV-Visible SpectroscopyUltraviolet-visible (UV-Vis) spectrophotometers are used to measure the interaction of UV and visible light with a sample, including transmission, reflectance & absorbance. The two major instrument classes are single-beam or double-beam spectrophotometers. More specialized equipment includes colorimeters, spectroradiometers and refractometers. Portable and microvolume spectrophotometers are also available. For the modular spectroscopy lab, explore a range of light sources for combination with a spectrograph/spectrometer and optics. Find the best UV-Vis spectroscopy products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Forensic InvestigationForensic investigation is a diverse collection of scientific techniques and methods for the identification and characterization of chemicals relating to crime scene investigations.

