Independent study confirms Raman Spectroscopy is effective on Questioned Documents

In a recent analysis of the surface enhanced resonance Raman scattering (SERRS) obtained from ballpoint pen inks, a group of researchers at a Dutch university reported that the technique was successful in differentiating the majority of the 26 inks examined. The authors also observed that the classifications obtained using ‘SERRS’ analysis matched those using the more conventional technique of thin layer chromatography (TLC), but that SERRS had the advantage of being less invasive and much faster than TLC.

The research was carried out at the Department of Analytical Chemistry and Applied Spectroscopy at the Free University, Amsterdam, the Netherlands, and is reported in the Analyst, 2001, 126, 1418-1422 entitled, "Applicability of surface-enhanced resonance Raman scattering for the direct discrimination of ballpoint pen inks", by Cees Gooijer et al. The SERRS spectra were obtained using Foster & Freeman’s Foram 685 Raman spectrometer, on loan to the university.

Publication of the work, which provides further evidence of the value of Raman spectroscopy in the examination of questioned documents, coincides with the launch of Foster & Freeman’s new Foram 685-2, an upgrade to the Foram 685, the company’s first Raman spectrometer launched in 1999.

The specification of the new instrument includes an improved A4 size XY translation stage, which makes fine positioning of a document easier and allows the operator to align the laser probe accurately on to particles of pigment as small as 5 microns. The integral video microscope has also been redesigned and is now fitted with a rotating turret to hold up to four objective lenses. This provides on screen magnification of up to ×500 to assist in the sample selection process. The instrument is also supplied with all the reagents and accessories necessary to generate SERRS spectra, comparable to those examined in the recently published study.

Click here to view the FORAM 685-2

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