On-line biological sample cleanup for electrospray mass spectrometry using sol-gel columns.
Using a slight overpressure, a urine sample is loaded onto a monolithic photopolymerized sol-gel column that has been derivatized with hydrophobic carbon chains and then the complex urine matrix is washed with aqueous solution. A buffer containing organic solvent is used to elute the adsorbed peptides by an applied voltage and the sample is then introduced into a mass spectrometer by sheath flow electrospray. The importance of desalting this type of sample is demonstrated by an experiment that shows that the signal intensity of a test solution with neurotensin, sprayed directly into the mass spectrometer, decreased from 4.5x10(4) cps to no detectible signal when just 10% urine is added to the sample solution. We suggest that this procedure may find general application for desalting biological samples prior to mass spectrometric analysis.
Johannesson
Nina
N
Uppsala University, Department of Physical and Analytical Chemistry, Uppsala, Sweden.
Pearce
Evan
E
Dulay
Maria
M
Zare
Richard N
RN
Bergquist
Jonas
J
Markides
Karin E
KE
D002853:Chromatography, Liquid / Q000379:methods; D005782:Gels; D008855:Microscopy, Electron, Scanning; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014556:Urine / Q000737:chemistry*
D005782:Gels