Separation of crystal violet dyes and its application to pen ink analysis using CZE and MEKC methods

Chun Min Shih, Ju Tsung Liu, Bo Hong Chen, Cheng Huang Lin

Research output: Contribution to journalArticle

10 Citations (Scopus)


A crystal violet (CV) standard was irradiated under a Hg-Cd lamp for different exposure times to obtain various N-demethylation products. CZE effectively separated the photodegradation products based on molecular weight differences. In contrast, micellar EKC (MEKC), using SDS as the surfactant, was ineffective because the binding constants of the demethylation products and SDS were too close for separation. Nevertheless, MEKC analysis of ink has applications in forensic science because MEKC separated neutral components in the inks. Thus, MEKC can be used to obtain an ink "fingerprint" since each ink is unique depending on the location and time it was made. In contrast, CZE is useful for dating inks because CV is the primary ink dye and it photodegrades slowly.

Original languageEnglish
Pages (from-to)893-897
Number of pages5
JournalJournal of Separation Science
Issue number5
Publication statusPublished - 2008 Mar 1



  • CZE
  • Crystal violet
  • Ink
  • MEKC
  • Methyl violet

ASJC Scopus subject areas

  • Molecular Medicine
  • Clinical Biochemistry
  • Chemical Engineering(all)
  • Filtration and Separation

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