59. Ionization Methods Soft method very high mass to 500,000 Daltons Sample mixed in solid matrix Peptides Proteins Nucleotides Matrix Assisted Laser Desorption (MALDI) Soft method but harder than ESI or MALDI to 6,000 Daltons Sample mixed in viscous matrix Carbohydrates Organometallics Peptides nonvolatile Fast Atom Bombardment (FAB) Soft method ions often multiply charged to 200,000 Daltons Liquid Chromatography or syringe Peptides Proteins nonvolatile Electrospray (ESI) Soft method molecular ion peak [M+H]+ to 1,000 Daltons GC or liquid/solid probe Relatively small volatile Chemical Ionization (CI) Hard method versatile provides structure info to 1,000 Daltons GC or liquid/solid probe Relatively small volatile Electron Impact (EI) Method Highlights Mass Range Sample Introduction Typical Analytes Ionization method