Sheathless capillary electrophoresis-mass spectrometry using a pulsed electrospray ionization source.
A sheathless interface has been developed for coupling CE with electrospray IT mass spectrometer. This interface utilized a pulsed ESI source. The use of a pulsed electrospray source allows the use of a sprayer with larger orifice, and thus alleviates the problem of column clogging during conductive coating and CE analysis. A pulsed ESI source operated at 20 Hz and 20% duty cycle was found to produce the optimal signals. For better signals, the maximum ion injection time in the IT mass spectrometer has to be set to a value close to the actual spraying time (10 ms). Using a sprayer with 50 microm od, more stable and enhanced signals were obtained in comparison with continuous CE-ESI-MS under the same flow rate (150 nL/min). The utility of this design is demonstrated with the analysis of synthetic drugs by CE-MS.
Chao
Bing-Fong
BF
Department of Chemistry, National Taiwan University, Taipei.
Chen
Chao-Jung
CJ
Li
Fu-An
FA
Her
Guor-Rong
GR
D019075:Electrophoresis, Capillary / Q000295:instrumentation*; D004364:Pharmaceutical Preparations / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation*
D004364:Pharmaceutical Preparations