Temperature-resolved thermal analysis of cisplatin by evolved gas analysis-mass spectrometry

Evolved gas analysis-mass spectrometry (EGA-MS), which has high sensitivity and is a simple experimental procedure, was used to study the non-isothermal decomposition of cisplatin at 45-500 °C. Unexpectedly, four peaks appeared in the total ion chromatogram starting at 235 °C, and analysis of the mass spectra of the peaks indicated that cisplatin was thermally unstable and lost NH₃ and HCl simultaneously at 235-385 °C. The molecular ion (M⁺) in the electron impact ionization spectrum of cisplatin was detected for the first time, which confirmed that cisplatin vaporized partially in molecular form. Various ion-molecule reactions occurred to form complex ions at m/z 370 and 335 at the higher part of the temperature range.