Temperature-resolved thermal analysis of cisplatin by means of Li+ ion attachment mass spectrometry.

Li(+) ion attachment mass spectrometry (IAMS) was evaluated as an analytical methodology for measurement of the thermally labile, nonvolatile, and insoluble compound cisplatin, which is used as an anticancer agent in the treatment of testicular and ovarian cancers. We aimed to develop an improved method for the mass spectrometric determination of cisplatin, particularly in its molecular ion form. A uniquely designed quadrupole mass spectrometry system along with a Li(+) ion attachment technique and a direct inlet probe provided cisplatin molecular ions as Li(+) ion adducts; to our knowledge this is the first reported instance of cisplatin Li(+) ion adducts. Full-scan spectra were obtained with approximately 10 microg samples. Infrared image furnace-ion attachment mass spectrometry (IIF-IAMS) also was used to study the temperature-programmed decomposition of this drug. The slope of the plot of signal intensity versus temperature for cisplatin decomposition from 225 to 249 degrees C was used to determine an apparent activation energy (E(a)) of 38.0 kcal mol(-1) for the decomposition of cisplatin. This decomposition parameter is useful for predicting drug stability (shelf life). In this study, we have demonstrated that IAMS can be a valuable technique for the direct mass spectral analysis and kinetic study of d-metal complex platinum anticancer agents.

Development of an ion attachment mass spectrometer for direct detection of intermediates in combustion flames.

A system with Li+ ion attachment (IA) ionization has been developed for the direct detection of intermediates formed in burning flames by mass spectrometry. Dimethyl ether (DME) among alternative fuels was selected as a test substance to examine the capability of the system. As a result, intermediates generated in a premixed DME-air flame were directly detectable as Li+ adduct ions. By moving the burner on an X-Y stage, spatial distribution profiles of different species, including unburned DME and formaldehyde, were obtained for three types of flames: diffusion, partially premixed, and premixed.

Development of a tabletop time-of-flight mass spectrometer with an ion attachment ionization technique.

We report a new type of mass spectrometry based on a time-of-flight mass spectrometer combined with an ion attachment ionization technique (IA-TOF). In contrast to electron ionization mass spectra, IA-TOF mass spectra are not complicated by peaks due to fragmentation of the molecular ion; the adduct ion formed in IA does not fragment. We developed a tabletop IA-TOF system and evaluated its performance by analyzing specimens originally in the gas, liquid, and solid phases. We obtained fragment-free spectra covering a mass range up to m/z 3400 with a mass resolution of about 4700. Our IA-TOF system realizes accurate and versatile real-time mass spectrometry.

Application of ion attachment mass spectrometry to evolved gas analysis for in situ monitoring of porous ceramic processing.

Ion attachment mass spectrometry was applied to evolved gas analysis-mass spectrometry (EGA-MS), generally known as thermogravimetry-mass spectrometry. Characteristic species arising from poly(vinyl alcohol) (PVA) and poly(methyl methacrylate) (PMMA) resin, used as a binder and a porogen, respectively, in the starting materials for porous ceramics, were detected in the mass spectra. The EGA curves of the characteristic mass peaks from PVA and PMMA, when plotted against the programmed temperature, successfully showed the individual pyrolysis behavior of each polymer during the firing process.