title: MALDI ion trap mass spectrometer with charge detector for large biomolecule detection.
abstract: Up to now, all commercial matrix-assisted laser desorption/ionization (MALDI) mass spectrometers still can not efficiently analyze very large biomolecules. In this work, we report the development of a novel MALDI ion trap mass spectrometer which can enrich biomolecular ions to enhance the detection sensitivity. A charge detector was installed to measure the large ions directly. With this design, we report the first measurement of IgM with the mass-to-charge ratio (m/z) at 980 000. In addition, quantitative measurements of the number of ions can be obtained. A step function frequency scan was first developed to get a clear signal in the m/z range from 200,000 to 1,000,000.
authors.affiliation: Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Chien-Hsun
authors.initials: CH
authors.lastname: Chen
authors.forename: Jung-Lee
authors.initials: JL
authors.lastname: Lin
authors.forename: Ming-Lee
authors.initials: ML
authors.lastname: Chu
authors.forename: Chung-Hsuan
authors.initials: CH
authors.lastname: Chen
mesh_terms: D007075:Immunoglobulin M / Q000032:analysis*; D007477:Ions; D008970:Molecular Weight; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation*
chemical_list: D007075:Immunoglobulin M; D007477:Ions