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Fast atom bombardment mass spectrometry of cisplatin analogs
Author(s) -
Siegel Marshall M.,
Bitha Panayota,
Child Ralph G.,
Hlavka Joseph J.,
Lin YangI,
Chang Ted. T.
Publication year - 1986
Publication title -
biomedical and environmental mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0887-6134
DOI - 10.1002/bms.1200130106
Subject(s) - fast atom bombardment , mass spectrometry , accelerator mass spectrometry , cisplatin , chemistry , atom (system on chip) , radiochemistry , computer science , chromatography , medicine , parallel computing , surgery , chemotherapy
Cisplatin analogs of the type PtL A L B are thermally unstable, non‐volatile and highly insoluble. For these platinum coordination complexes, L A is a bidentate amine ligand and L B is a bidentate carboxylate ligand. Mass spectral data for structural elucidation of these compounds are absent in the literature because they are difficult to ionize. Nevertheless, a routine fast atom bombardment mass spectroscopic method has been developed utilizing the mixed solvent system of dimethyl sulfoxide: thioglycerol in a ratio of about 1:3 v/v. Using both positive and negative ionization modes, structurally significant ions were observed from representative molecules of the two named classes of compounds. [M H] − ions were observed in both structural classes while [M + H] + ions were observed only in the PtL A L B class of compounds. Additional ions observed are rationalized in terms of the condensed‐phase solution chemistry of the cisplatin analogs and the mixed solvent system when exposed to the fast atom beam. The two mechanisms causing ionization of the cisplatin analogs in the condensed phase appear to be: (i) displacement of the ligands with dimethyl‐sulfoxide and (ii) addition of chloride and the ionized solvents [dimentyl sulfoxide+H] + and [thioglycerolH] − to the cisplatin analogs. It is hypothesized that the addition reactions of the ionized solvents occur because of the differences in the basicity of the solvents and their reactivity in forming platinum(II)‐sulfur bonds.