Peripheral techniques in mass spectrometry

An understanding of these mechanisms enables the second aspect of mass spectrometry to be approached with more confidence. One of the results of this approach led 

The presence of easily detected and intense fragmentations also led to the possibility of studying complex mixtures quantitatively with techniques such as selected ion monitoring (SIM) and multiple ion detection (MID), which are used extensively especially when the mass spectrometer is coupled to a gas chromatograph. In their review, Lehman and Schulten [13] showed the various possibilities of these methods when mass spectrometry is applied quantitatively to biochemistry or medicine. It should be noted that these detection modes are valid even at high resolution ( 10,000) [14,15]. 

In the fields of pharmacology, toxicology and medicine, Jellum [16] showed how GC/MS opened the door to new possibilities. His exhaustive work describes the problems associated with GC/MS, as well as those involved with the processing of the data obtained. The use of stable isotopes for these studies is a non-negligible contribution, as shown by Krahmer and McCloskey [17] during the development of this methodology. Klein and Klein [18,19] performed a veritable census of labeled molecules so far prepared for these analyses. 

During the last few years, a considerable number of reviews (prior to 1981) have appeared on the subject of GC/MS [20] and also on the new possibilities offered by LC/MS [21,22], which seems to have a promising future. Computer-assisted data processing has enabled workers to study complex problems, even when only a very small sample is available. The rapid repetition of such measurements leads to sufficient precision, even at high resolution [23]. 

It is difficult to give an exhaustive list of the various possibilities which simplify analytical and structural MS studies, in particular in the fields of natural and biological products. We wish to stress, however, the particular importance of computer-assisted data processing, used to determine the structure of these compounds in a mixture and even in trace amounts [24], 

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