Detection of symmetrical decomposition of molecules--isotopomeric analysis of the M/2 clusters.

The interpretation of mass spectra (ms) of molecules containing poly-isotopic elements (e.g. Ge, Se, W, Os, Sn, Te, Zn, Yb) can be difficult due to the occurrence of fragments resulting from isotopomeric composition. MS-clusters located in the range lower than or equal to M/2 are very difficult to interpret. In this area many perturbations may be observed. The coincidence of different fragmentation pathways, the existence of multiply charged ions, background levels, etc. can all contribute to this problem. The present paper reports the application of multi-isotopomeric analysis methods for low-resolution ms. We present a solution that may be useful for detection of the symmetrical decomposition of a molecule and for elucidation of cluster ion genesis. The complex character of the cluster does not perturb determination of the contents of the investigated pattern. In such cases the dominated component is applied in subsequent computations.