Ballpoint Pen Inks: Characterization by Positive and Negative Ion-Electrospray Ionization Mass Spectrometry for the Forensic Examination of Writing Inks

    Volume 47, Issue 6 (November 2002)

    ISSN: 0022-1198

    CODEN: JFSOAD

    Published Online: 1 November 2002

    Page Count: 10


    Ng, LK
    Research scientist, research technologist, and forensic investigation analyst, Canada Customs and Revenue Agency, Ottawa, Ontario

    Brazeau, L
    Research scientist, research technologist, and forensic investigation analyst, Canada Customs and Revenue Agency, Ottawa, Ontario

    Lafontaine, P
    Research scientist, research technologist, and forensic investigation analyst, Canada Customs and Revenue Agency, Ottawa, Ontario

    (Received 10 May 2002; accepted 4 May 2002)

    Abstract

    A method based on profiling of dye components by electrospray ionization mass spectrometry (ESI/MS) is described for the characterization of ballpoint pen inks. The method involves benzyl alcohol (30 _L) extraction of ink from paper. The extracts of ink lines 1 and 5 mm in length are used for direct ESI/MS analysis in positive and negative modes, respectively. The instrumental analysis takes 3 min. Basic and acid dyes in the inks are detected in the positive and negative modes, respectively, with each dye yielding one or two characteristic ion peaks. The mass spectrum, which is mainly a compositional signature of the dyes in the ink, was not affected by the type of paper from which the ink was extracted, or by natural ageing of the ink on document in the absence of light. However, exposure to fluorescent illumination caused dealkylation of polyalkylated basic dyes and resulted in changes in the homologous distribution of the dyes. In this study, a total of 44 blue inks, 23 black inks, and 10 red inks have been analyzed, and the mass spectra were used to establish a searchable library. ESI/MS analysis provides a simple and fast way to compare ink specimens and in combination with on-line library search permits rapid screening of inks for forensic document investigations.


    Paper ID: JFS15555J

    DOI: 10.1520/JFS15555J

    ASTM International
    is a member of CrossRef.

    Author
    Title Ballpoint Pen Inks: Characterization by Positive and Negative Ion-Electrospray Ionization Mass Spectrometry for the Forensic Examination of Writing Inks
    Symposium , 0000-00-00
    Committee E30