Electron impact mass spectrometry of 2-ary-thiazolidinecarboxylic acids

The mass spectrometric behaviour of 11 2-aryl-thiazolidine-4-carboxylic acids has been studied under electron impact conditions. On the basis of our high- and low-resolution measurements, deuterium labelling experiments and collision-induced dissociation studies the main fragmentation pathways have been established. In the high resolution spectrum of 2-phenyl-thiazolidine- 4-carboxylic acid several peaks were found to be doublets. Some of the chemical formulae were unexpected. With the help of tandem mass spectrometry the formation of these ions was explained.