Detection of trace ink compounds in erased handwritings using electrospray-assisted laser desorption ionization mass spectrometry

Yi Ying Kao, Sy Chyi Cheng, Chu Nian Cheng, Jentaie Shiea, Hsiu O. Ho

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10 Citations (Scopus)


Writings made with erasable pens on paper surfaces can either be rubbed off with an eraser or rendered invisible by changing the temperature of the ink. However, trace ink compounds still remain in the paper fibers even after rubbing or rendering. The detection of these ink compounds from erased handwritings will be helpful in knowing the written history of the paper. In this study, electrospray-assisted laser desorption ionization/mass spectrometry was used to characterize trace ink compounds remaining in visible and invisible ink lines. The ink compounds were desorbed from the paper surface by irradiating the handwritings with a pulsed laser beam; the desorbed analytes were subsequently ionized in an electrospray plume and detected by a quadrupole time-of-flight mass spectrometry mass analyzer. Because of the high spatial resolution of the laser beam, electrospray-assisted laser desorption ionization/mass spectrometry analysis resulted in minimal damage to the sample documents.

Original languageEnglish
Pages (from-to)445-451
Number of pages7
JournalJournal of Mass Spectrometry
Issue number6
Publication statusPublished - 2014



  • document examination
  • electrospray-assisted laser desorption ionization
  • erasable ink
  • forensic science
  • mass spectrometry

ASJC Scopus subject areas

  • Spectroscopy
  • Medicine(all)

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