Microscopy with direct analyte-probed nanoextraction coupled to nanospray ionization mass spectrometry (DAPNe-NSI-MS) is a direct extraction technique that extracts ultra-trace amounts of analyte. It has been proven to extract ink from documents with little to no physical or chemical footprint. In the current study, a handwritten number was altered using a different ink pen to test whether the aforementioned techniques could discriminate the original number from the altered number, qualitatively and/or quantitatively. Chemical species from part of the original number, altered number, and a point at which both inks intersect were successfully differentiated by all techniques when using different pens. DAPNe coupled to fluorescence microscopy and Raman spectroscopy was not able to discriminate the forged ink entry when the exact same pen was used to modify the text (due to the same ink formula); however, DAPNe-NSI-MS successfully discerned that the pen was dispensed on different days by quantitating the oxidation process. (publisher abstract modified)
Downloads
Similar Publications
- Investigation into Using Entomology to Improve Methods of Anthropological Post-mortem Interval Estimation
- Mineralogy and Geochemistry of Sands from Playa Las Golondrinas, Puerto Rico: An Approach to Establishing a Geogenic Background
- SNP Miniplexes for Individual Identification of Random-Bred Domestic Cats