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Nanomanipulation-Coupled to Nanospray Mass Spectrometry Applied to Document and Ink Analysis

NCJ Number
Forensic Science International Volume: 242 Dated: September 2014 Pages: 150-156
Date Published
September 2014
7 pages
This article reports on the development of a method for the extraction and analysis of ink samples, using microscopy with direct analyte probe nanoextraction coupled to nanospray ionization mass spectrometry (DAPNe-NSI-MS) for localized chemical analysis of document inks.

Nanomanipulation can be effectively coupled to nanospray ionization mass spectrometry, providing picomolar sensitivity and the capability to analyze ultra-trace amounts of material and reduce the required sample volume to as low as 300 nL. This new and innovative technique does not leave destructive footprints on the surface of a document. To demonstrate the breadth of this technique, analysis was conducted of inks from various eras, iron gall ink, and modern inks, as well as the capability to detect the oxidative products of polyethylene glycol (PEG), a common binding agent. The experimental results showed that DAPNe-NSI-MS was able to chelate iron(II) and manganese(II) ions of iron gall ink and organic components of modern and carbon-based inks. Regardless of whether the ink composition is modern or ancient, organic or inorganic, this new instrumental approach can identify and characterize the ingredients by modifying the extraction solvent, illustrating the potential diversity of the DAPNe technique. (publisher abstract modified)

Date Published: September 1, 2014