title: Interfacing liquid chromatography with atmospheric pressure MALDI-MS.
abstract: Two different strategies for coupling liquid chromatography with atmospheric pressure matrix assisted laser desorption/ionization (AP MALDI) are presented. The first method is flow-injection liquid AP UV-MALDI. Compared with previous similar research, the detection limit was improved 10 times to 8.3 fmol using a solution of 50 nM peptide with 25 mM alpha-cyano-4-hydroxycinnamic acid. The applicability of this method to measure oligosaccharides, actinomycin antibiotics, antibiotics, phosphopeptides, and proteins is demonstrated. The upper mass limit achieved with the current instrumentation is 6,500 Da (doubly charged cytochrome c). The feasibility of a second strategy based on single-droplet IR AP MALDI is demonstrated here. Aqueous peptide solutions were successfully measured by this method.
authors.affiliation: Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, (ETH),Hönggerberg, 8093 Zürich, Switzerland.
authors.forename: Jürg M
authors.initials: JM
authors.lastname: Daniel
authors.forename: Victor V
authors.initials: VV
authors.lastname: Laiko
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Doroshenko
authors.forename: Renato
authors.initials: R
authors.lastname: Zenobi
mesh_terms: D001274:Atmospheric Pressure; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods; D003373:Coumaric Acids / Q000494:pharmacology; D017022:Flow Injection Analysis / Q000379:methods; D010455:Peptides / Q000494:pharmacology; D011422:Propionates; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods
chemical_list: D003373:Coumaric Acids; D010455:Peptides; D011422:Propionates; C495469:p-coumaric acid