title: High-mass MALDI-MS using ion conversion dynode detectors: influence of the conversion voltage on sensitivity and spectral quality.
abstract: With the development of special ion conversion dynode (ICD) detectors for high-mass matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), the mass-to-charge ratio is no longer a limiting factor. Although these detectors have been successfully used in the past, there is lack of understanding of the basic processes in the detector. We present a systematic study to investigate the performance of such an ICD detector and separate the contributions of the MALDI process from the ones of the ion-to-secondary ion and the secondary ion-to-electron conversions. The performance was evaluated as a function of the voltages applied to the conversion dynodes and the sample amount utilized, and we found that the detector reflects the MALDI process correctly: limitations such as sensitivity or deviations from the expected signal intensity ratios originate from the MALDI process itself and not from the detector.
authors.affiliation: Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093, Zürich, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Weidmann
authors.forename: Renato
authors.initials: R
authors.lastname: Zenobi
mesh_terms: D007477:Ions / Q000032:analysis / Q000737:chemistry; D008970:Molecular Weight; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods*
chemical_list: D007477:Ions; D011506:Proteins