Differentiation of blue ballpoint pen inks by positive and negative mode LDI-MS

Details

Serval ID
serval:BIB_FF112EA23B4F
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Differentiation of blue ballpoint pen inks by positive and negative mode LDI-MS
Journal
Forensic Science International
Author(s)
Gallidabino M., Weyermann C., Marquis R.
Publication state
Published
Issued date
01/2011
Peer-reviewed
Oui
Volume
204
Number
1-3
Pages
169-178
Language
english
Abstract
Usually, the differentiation of inks on questioned documents is carried out by optical methods and thin layer chromatography (TLC). Therefore, spectrometric methods were also proposed in forensic literature for the analysis of dyes. Between these techniques, laser desorption/ionization mass spectrometry (LDI-MS) has demonstrated a great versatility thanks to its sensitivity to blue ballpoint ink dyes and minimal sample destruction. Previous researches concentrated mostly on the LDI-MS positive mode and have shown that this analytical tool offers higher discrimination power than high performance TLC (HPTLC) for the differentiation of blue ballpoint inks. Although LDI-MS negative mode has already been applied in numerous forensic domains like the studies of works of art, automotive paints or rollerball pens, its potential for the discrimination of ballpoint pens was never studied before. The aim of the present paper is therefore to evaluate its potential for the discrimination of blue ballpoint inks. After optimization of the method, ink entries from 33 blue ballpoint pens were analyzed directly on paper in both positive and negative modes by LDI-MS. Several cationic and anionic ink components were identified in inks; therefore, pens were classified and compared according to their formulations. Results show that additional information provided by anionic dyes and pigments significantly increases the discrimination power of positive mode. In fact, it was demonstrated that classifications obtained by the two modes were, to some extent, complementary (i.e., inks with specific cationic dyes not necessarily contained the same anionic components).
Keywords
Criminalistic, Questioned documents, Ballpoint, Ink, Mass spectrometry, LDI, Discrimination power
Create date
10/01/2011 11:50
Last modification date
20/08/2019 17:29
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