Differentiating writing inks using direct analysis in real time mass spectrometry.

Analysis of writing inks on paper using direct analysis in real time mass spectrometry.

Ink analysis is central to questioned document examination. We applied direct analysis in real time mass spectrometry (DART MS) to ballpoint, gel, and fluid writing ink analysis. DART MS acquires the mass spectrum of an ink while it is still on a document without altering the appearance of the document. Spectra were acquired from ink on a variety of papers, and the spectrum of the blank paper c...

Characterization of ballpoint pen inks by thermal and desorption and gas chromatography-mass spectrometry.

The characterization of ink on paper is of importance for dating and comparing questioned ink entries in forensic document examination. Inks are commonly characterized by their colorant profile that is identified by well-established analytical methods. Numerous ink formulations show identical colorant profiles, though. In order to differentiate inks that are not distinguishable by colorant anal...

Analysis of self-assembled monolayers on gold surfaces using direct analysis in real time mass spectrometry.

Mass spectrometry was performed on self-assembled monolayers (SAMs) of dodecanethiol on gold using the new direct analysis in real time (DART) ionization technique. Observed peaks for the SAMs included monomers, dimers, and trimers of the SAM molecules, with the dimer and trimer relative peak heights enhanced as compared to the spectra for neat dodecanethiol. The possibility that the observed p...

The use of laser desorption/ionization mass spectrometry in the analysis of inks in questioned documents.

Determination of the age of a handwritten or ink printed questioned document can be an important consideration in forensic cases. Most often the age of a document is determined by the chemical behavior of the dyes that make up the ink. Exposure of the dyes to environmental factors such as oxygen and ultraviolet or visible light cause them to degrade. Often this degradation can be correlated to ...

Surface swabbing technique for the rapid screening for pesticides using ambient pressure desorption ionization with high-resolution mass spectrometry.....................4 Rapid screening for synthetic antidiabetic drug adulteration in herbal dietary supplements using direct analysis in real time mass spectrometry