Ion trap mass spectrometry as detector for capillary electrochromatography of peptides: Possibilities and limitations

Capillary electrochromatography has been coupled to an ion trap mass spectrometer via a sheath flow electrospray interface. Peptide analysis was performed on 25 cm columns packed with C₁₈-bonded silica particles, and very fast separations were obtained. Full mass spectrometry and tandem mass spectrometry (MS/MS) detection were evaluated in terms of sensitivity and scanning speed. The separation of seven selected peptides and their detection by MS/MS in selected reaction monitoring mode was demonstrated. The performance of this sheath flow interface also was compared with the previously reported sheathless interface. Despite the loss in sensitivity (20–40-fold), the sheath flow interface was shown to be superior in terms of ruggedness, and allowed the use of higher electric fields to achieve faster analysis times. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 243–249, 2001