title: On-line atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry.
abstract: A new technique is presented for the coupling of atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) mass spectrometry with liquid delivery systems. Mass measurements of polymers and peptides are demonstrated using a co-dissolved matrix, e.g. alpha-cyano-4-hydroxycinnamic acid (HCCA). Improvements in terms of sensitivity are achieved by optimizing the shape und control of the exit capillary and by using a laser (355 nm) at a 1 kHz repetition rate. Two calibration experiments promise a good applicability of the presented coupling method for quantitative measurements. The limit of detection achieved so far is 500 nM for peptides in methanol solution containing 25 mM HCCA.
authors.affiliation: Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland.
authors.forename: Jurg M
authors.initials: JM
authors.lastname: Daniel
authors.forename: Sille
authors.initials: S
authors.lastname: Ehala
authors.forename: Sebastian D
authors.initials: SD
authors.lastname: Friess
authors.forename: Renato
authors.initials: R
authors.lastname: Zenobi
mesh_terms: D000818:Animals; D017022:Flow Injection Analysis; D011506:Proteins / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D011506:Proteins