Arifov Institute of Electronics of Uzbek Academy of Sciences, Tashkent, Uzbekistan

This work demonstrates the possibilities of the SI mass-spectrometry in highly sensitive and selective analysis of psychotropic preparations from phenothiazine derivatives. Chlorpro-mazine manufactured in Russia was tested as a representative of the aliphatic group of phenothiazines, tioproperazine of pyperazine group, and periciazine (manufactured in France) was chosen as a representative of the pyperidine group.

The experiments have shown that the regularities of formation of the SI mass-spectra obey the general rules. However, the presence of two or more heteroatoms in a molecule leads to additional channels of molecule dissociation. In spite of this the mass-spectra are of few lines. Their composition and the temperature dependencies of ion currents demonstrate a high efficiency of formation of quasimolecular ions [M-H]+ and of fragments ions [M-Ri]+ (where M is a molecule, H is a hydrogen atom, Ri is a radical) which do not contain uncoupled electrons.

Under optimum experimental conditions the [M-H]+ ion intensities may reach up to 60% for chlorpromazine, 50% for tioproperazine and 10-15% for periciazine. The peculiarities of mass-spectra formation connected with the possible pathways of decay of molecules on the surface are discussed. The estimations show the amount of substance necessary for reliable identification was only 1 ng.