Oxygen Diffusion in Tungsten
INFORMATION concerning oxygen diffusion in tungsten is technologically valuable for many reasons. One such reason is its important role in the development of the structural properties of tungsten for high-temperature applications.
Important Aspects of Tungsten Chemistry
Tungsten’s sensitivity toward oxygen restricts its high-temperature application to protecting atmospheres or vacuum only.
Formation of unexpected ions from a first-generation polyamidoamine dendrimer by use of methanol: an artefact due to electrospray emitter corrosion?
We report the formation of unexpected ions during the analyses of a first-generation polyamidoamine dendrimer in negative ion mode using an ion trap equipped with an electrospray ionisation source. These surprising ions corresponded to an increase of 12 m/z units over those expected. The formation of the unexpected ions was dependent on the tuning of the solution flow rate and the capillary high voltage. In addition, measurements of unusual value of the current suggested that a reaction was occurring in the corona plasma. The influence of methanol in this phenomenon was demonstrated by using CD(3)OH in the sample preparation. We propose two structures to explain the observed adduct based on the results of MS(2) experiments and by referring to previous work dealing with 12 m/z units addition. We showed that a corona discharge caused by alterations taking place to the electrospray capillary emitter was the origin of these unexpected ions. Finally, we discuss the mechanism involved in the formation of the ions and we propose means to control such artefacts.