the strength of the external magnetic field and on the characteristics of the nucleus being examined. The nucleus of the proton, placed in 14, 100 gauss field, undergoes resonance when irradiated with radiation in the 60 MHz range microwave radiation): higher magnetic fields, such as those common in superconducting magnets, require higher energy radiation and give a correspondingly higher resolution. Use the menu above to move to review sections on other topics in NMR spectros copy. Mass Spectrometry- Background In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule. The positive fragments which are produced (cations and radical cations) are accelerated in a vacuum through a magnetic field and are sorted on the basis of mass-to-charge ratio. Since the bulk of the ions produced in the mass spectrometer carry a unit positive charge, the value mye is equivalent to the molecular weight of the fragment. The analysis of mass spectroscopy information involves the re-assembling of fragments, working backwards to generate the original molecule. A schematic representation of a mass spectrometer is shown below Magnetic Field Bends Path of Charged Source G lon Accelerating Collector Exit slit H A very low concentration of sample molecules is allowed to leak into the ionization chamber (which is under a very high vacuum)where they are bombarded by a high-energy electron beam. The molecules fragment and the positive ions produced are accelerated through a charged array into an analyzing tube. The path of the charged molecules is bent by an applied magnetic field. Ions having low mass (low momentum) will be deflected most by this field and will collide with the walls of the analyzer. Likewise, high momentum ions will not be deflected enough and will also collide with the analyzer wall. Ions having thethe strength of the external magnetic field and on the characteristics of the nucleus being examined. The nucleus of the proton, placed in 14,100 gauss field, undergoes resonance when irradiated with radiation in the 60 MHz range (microwave radiation); higher magnetic fields, such as those common in superconducting magnets, require higher energy radiation and give a correspondingly higher resolution. Use the MENU above to move to review sections on other topics in NMR spectroscopy. M a ss S pectrometry - B a ckground In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule. The positive fragments which are produced (cations and radical cations) are accelerated in a vacuum through a magnetic field and are sorted on the basis of mass-to-charge ratio. Since the bulk of the ions produced in the mass spectrometer carry a unit positive charge, the value m/e is equivalent to the molecular weight of the fragment. The analysis of mass spectroscopy information involves the re-assembling of fragments, working backwards to generate the original molecule. A schematic representation of a mass spectrometer is shown below: A very low concentration of sample molecules is allowed to leak into the ionization chamber (which is under a very high vacuum) where they are bombarded by a high-energy electron beam. The molecules fragment and the positive ions produced are accelerated through a charged array into an analyzing tube. The path of the charged molecules is bent by an applied magnetic field. Ions having low mass (low momentum) will be deflected most by this field and will collide with the walls of the analyzer. Likewise, high momentum ions will not be deflected enough and will also collide with the analyzer wall. Ions having the