Time-of-flight secondary ion tandem mass spectrometry depth profiling of organic light-emitting diode devices for elucidating the degradation process.

Rationale: Organic light-emitting diode (OLED) products based on display applications have become popular in the past 10 years, and new products are being commercialized with rapid frequency. Despite the many advantages of OLEDs, these devices still have a problem concerning lifetime. To gain an understanding of the degradation process, the authors have investigated the molecular information for deteriorated OLED devices using time-of-flight secondary ion mass spectrometry (TOF-SIMS).

Secondary ion yields for vacuum-type electrospray droplet beams measured with a triple focus time-of-flight analyzer.

Rationale: We previously developed a massive cluster ion beam gun for secondary ion mass spectrometry (SIMS) in which the primary beam source is a vacuum electrospray. The secondary ion yields produced by this method had not yet been measured with a commercial time-of-flight (TOF) secondary ion mass spectrometer, and the ionization performance was unknown.

Methods: A vacuum-type electrospray droplet ion gun was connected to a triple-focus TOF analyzer.

Palmitic acid, verified by lipid profiling using secondary ion mass spectrometry, demonstrates anti-multiple myeloma activity.

Recent studies indicate that lipid metabolic changes affect the survival of multiple myeloma (MM) cells. Time-of-flight secondary ion mass spectrometry (TOF-SIMS), an imaging mass spectrometry technique, is used to visualize the subcellular distribution of biomolecules including lipids. We therefore applied this method to human clinical specimens to analyze the membrane fatty acid composition and determine candidate molecules for MM therapies.

Argon cluster ion beams for organic depth profiling: results from a VAMAS interlaboratory study.

The depth profiling of organic materials with argon cluster ion sputtering has recently become widely available with several manufacturers of surface analytical instrumentation producing sources suitable for surface analysis. In this work, we assess the performance of argon cluster sources in an interlaboratory study under the auspices of VAMAS (Versailles Project on Advanced Materials and Standards). The results are compared to a previous study that focused on C(60)(q+) cluster sources using similar reference materials.