title: On-probe solid-phase extraction/MALDI-MS using ion-pairing interactions for the cleanup of peptides and proteins.
abstract: Samples originating from biological sources often contain a complex mixture of inorganic salts, buffers, chaotropic agents, surfactants/detergents, preservatives, and other solubilizing agents. However, the presence of these contaminants virtually ensures the failure of any subsequent analysis of the sample by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Sample cleanup procedures, therefore, must be performed prior to MALDI-MS analysis. This paper reports a probe-surface derivatization method that greatly simplifies this sample preparation process. MALDI probes possessing self-assembled monolayers (SAMs) terminated with ionic functional groups can rapidly extract peptides/proteins via ionic interactions from < or = 1-microL volumes of sample solutions placed directly on their surface. We have found that MALDI probes modified in this manner are a practical solution for analyzing very small volumes of peptide/protein solutions contaminated with high levels of inorganic salts, buffers, detergents, chaotropic agents, and other solubilizing agents.
authors.affiliation: Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Warren
authors.forename: A H
authors.initials: AH
authors.lastname: Brockman
authors.forename: R
authors.initials: R
authors.lastname: Orlando
mesh_terms: D007202:Indicators and Reagents; D010455:Peptides / Q000032:analysis / Q000302:isolation & purification*; D011506:Proteins / Q000032:analysis / Q000302:isolation & purification*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007202:Indicators and Reagents; D010455:Peptides; D011506:Proteins