ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The application of the superposition principle of McLafferty and co-workers to collision induced dissociation or collisional activation spectra to obtain quantitative estimates of the composition of isomeric mixtures of ions is discussed in detail. A set of explicitly stated assumptions is used to derive expressions for the percent composition based on normalized peak heights or peak height ratios in the collision induced dissociation spectra. The simple linear interpolation based on peak ratios which has been used in the past is shown to be invalid. It is demonstrated that the common practice of ignoring those collision induced dissociation peaks where there is interference from non-collision induced dissociation processes may lead to substantial uncertainty in the final results. It is also demonstrated that the superposition principle may lead to results which are not internally consistent with the model. The final conclusion is that the present method of quantitative structural analysis based on the superposition principle cannot generally be expected to yield reliable results. In specific cases the results may be assumed to be reliable if it is demonstrated that the model is self-consistent and the inherent experimental uncertainty is reasonably small. Further work may be useful in developing a generally valid method of analysis.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210170507
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