Analysis of histones by on-line capillary zone electrophoresis-electrospray ionisation mass spectrometry

The on-line combination of capillary electrophoresis and electrospray ionis ation mass spectrometry was applied for the determination of some basic his tones from calf thymus. The separation performance of those basic proteins was significantly improved by coating the capillaries with hydroxypropylmet hylcellulose. The coating appeared to mask effectively the underlying silan ol groups thus avoiding undesirable adsorption of the histones onto the cap illary walls, while it was also shown to be an effective way to avoid conta mination of the mass spectrometer. Finally, capillary electrophoresis-elect rospray ionisation mass spectrometry with coaxial sheath liquid was success fully applied to the analysis of histones using a simple dialysis step of t he sample as sample pretreatment. (C) 2001 Elsevier Science B.V. All rights reserved.