Mass fragmentometry

The sensitivity of GC-MS can be increased still further by selective ion current monitoring (SICM) whereby only a limited number of characteristic ions in the mass spectrum of the compound are monitored. Therefore the time for which each ion is monitored, and hence the sensitivity, is increased so that the amount of an identifiable GA is reduced to 10 T 4 g. As in mass fragmentometry, sufficient ions must be monitored for an identification to be made. 

Mass spectrometry may be characterized by successful results in the field of biochemistry this success is due above all to the development of GC/MS (and LC/MS), combined with a computer for rapid data processing. The use of mass fragmentometry (SIM, MID) has resulted in assays of very small quantities in mixtures (currently on the order of a pg, and even a fg, scale). 

Sano M, Yotsui Y, Abe H, Sasaki S (1976) A new technique for the detection of metabolites labelled by the isotope 13C using mass fragmentometry. Biomed Mass Spectrom 3, 1-3. 

For high-sensitivity applications (e.g., less than 50 pg of injected DA, NE, etc.), it is absolutely essential to have a detector chamber and WE with the smoothest possible surfaces. New users of the technique often seem to feel this requirement is some magic or art which has little place in scientific methodology. But, one must remember that this simple detector system is operating at sensitivities that rival those of mass fragmentometry or... 

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