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Separation of crystal violet dyes and its application to pen ink analysis using CZE and MEKC methods
Author(s) -
Shih ChunMin,
Liu JuTsung,
Chen BoHong,
Lin ChengHuang
Publication year - 2008
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200700509
Subject(s) - crystal violet , chromatography , inkwell , triarylmethane dye , chemistry , materials science , medicine , pathology , composite material
Abstract 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.