CHEM 2OA3 Chapter Notes -Decane, Benzene, Mass Spectrum
Document Summary
Mass spectrometry is primarily used to determine the molar mass and formula for a compound. High performance chromatography to separate compounds, mass spectrometry to analyze the structure of the compounds. Electron impact ionization: generate an intermediate that is both a cation and a radical. Radical : unpaired electron; cation: bears a positive charge. Fragments results, neutral radical and a charged carbocation. Charge move and interact with a magnetic field, accelerated to a negatively charged plate, bent over to one side and arrive at the detector. The mass spectrum is to measure the amount of atoms arrive at the detector as a function of mass. X axis is mass. m/z (mass to charge ratio) z:charge. For an unknown compound, read the mass spectrum, and then get the molecular weight. Read the peak furthest to the right. The smaller bars are fragment ions, created by the fragments from the parent ion, losing hydrogen ions. 17 is a result of an isotope c17.