2.Mass spectrometry

• Mass spectrometry can be used to find relative isotopic masses, abundance of different isotopes of an element, and relative molecular mass, Mr, of compound( given by molecular ion peak on spectrum. The mass / charge (m/z) value of molecular ion peak is equal to Mr of molecule
• High resolution mass spectrometers can measure atomic and molecular masses extremely accurately (to several decimals places). Useful for identifying compounds that appear to have same Mr when they’re rounded to nearest whole number. E.g propane (C3H8) and ethanol (CH3CHO) both have Met of 44 to nearest whole number. But in high resolution mass spectrum, propane has molecular ion peak with m/z = 44.0624 and ethanol as m/z = 44.0302