A theoretical and experimental study of the fragment ion of m/z 97 obtained from the dimethyl disulfide derivative of unsaturated ethyl esters

An experimental and a theoretical study have been undertaken on the very la rge fragment ion of m/z 97 observed in the mass spectra of dimethyl disulfi de (DMDS) derivatives of methyl esters, A structure for this ion and the co rresponding fragmentation pathway have been proposed, This fragment ion is present only when one methylene group separates the double bonds and only i f the compounds contain an ester function. The presence of this fragment io n allows the easy location of the double bonds.