Fully on-line hyphenation of an experimental OPLC separation unit with diode-array detection and mass-spectrometry (OPLC-DAD-MS) for analysis of xanthine compounds

Research output: Article

12 Citations (Scopus)


The newly developed experimental OPLC separation unit 100 (OSU 100) has been used for fully on-line multiple hyphenation using the one-channel flowing eluent wall (FEW) arrangement at the inlet. OSU 100-UV and OSU 100-DAD-ESI-MS with manual injector or autosampler were used to test the connected systems (OPLC-UV; OPLC-DAD-ESI-MS), using xanthine standards (caffeine, theophylline, theobromine) and green tea leaf extract as model compounds. The mobile phase chloroform-trifluoroacetic acid-acetonitrile-methanol, 76:4:6.67:13.33 (ν/ν) is suitable for rapid and selective separation, DAD, and ESI-MS of xanthines. The detection sensitivity of OPLC-UV or OPLC-DAD was increased by hyphenation with ESI-MS coupled in series. In contrast with DAD, the extracted ion chromatogram (m/z = 181.1 Da) after background subtraction yields readily measurable peaks from the small amounts of theophylline and theobromine in tea leaf extract. Analysis of xanthines was achieved within 10 min with less than 2 mL mobile phase. Owing to the openable adsorbent layer in OPLC the bed conditions can, moreover, be checked off-line after single or multiple fully online separations.

Original languageEnglish
Pages (from-to)361-366
Number of pages6
JournalJournal of Planar Chromatography - Modern TLC
Issue number5
Publication statusPublished - okt. 1 2008


ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Clinical Biochemistry

Cite this