Mass spectrometry has become a vital tool in the hands of organic chemists and biochemists because of its potential to supply definitive, qualitative and quantitative information on molecules based on their structural compositions.

Sample Required

About 1mg. The sample required can be in the solid or liquid state. Sample should be pure and free from solvents and metal ions

Applications.

  • Structural elucidation of organic compounds
  • Mechanistic study of fragmentation process under mass spectrometric condition
  • Molecular weight and structural analysis of large biomolecules.
 

Description

The Mass spectrometer consists of an ion source, an analyzer and a detector maintained at a vacuum of 10-8 torr. The vaporized molecules are first bombarded by a stream of high energy electrons converting some of the molecules into molecular ions and fragment ions. The ions are accelerated and separated according to their mass to charge ratios in the magnetic field (analyzer). These are then velocity focussed in an electric field. The ions are detected in terms of their mass to charge ratios by the detector namely a secondary electron multiplier. The output is amplified and fed to the recorder for processing. The mass spectrum, a graph of intensity of the ions detected vs. m/z value is presented on the screen and printed. An IBM compatible PC is used to control the Mass spectrometer and also to acquire, process and print out the spectral data.

The Finnigan MAT 8230 GC-MS with Data system is a high resolution, double focussing instrument with reverse Nier-Johnson geometry. The maximum resolution is 48000 at 10% valley in low resolution mode. Maximum calibrated mass is 1500 Daltons.

 

 

Source options available are:

  1. Electron impact (EI)
  2. Chemical ionization (CI)
  3. Fast atom bombardment (FAB)

The types of analyses possible are


  1. Normal positive ion mass spectra in EI / CI / FAB mode
  2. Negative ion mass spectra in EI / CI / FAB
  3. High-resolution analysis
  4. Daughter-ion analysis in the first field-free region (B/E linked-scan)
  5. Parent-ion analysis in the first field-free region (B2/E linked-scan
  6. Collision activity decomposition spectra of any particular ion in the first field free region
  7. GC-MS analysis

 

 

 
 
 
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