The Composition of Saturated Vapor over 1-Butyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid: A Multi-Technique Study of the Vaporization Process.

A multi-technique approach based on Knudsen effusion mass spectrometry, gas phase chromatography, mass spectrometry, NMR and IR spectroscopy, thermal analysis, and quantum-chemical calculations was used to study the evaporation of 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF). The saturated vapor over BMImBF was shown to have a complex composition which consisted of the neutral ion pairs (NIPs) [BMIm][BF], imidazole-2-ylidene CNHBF, 1-methylimidazole CNH, 1-butene CH, hydrogen fluoride HF, and boron trifluoride BF. The vapor composition strongly depends on the evaporation conditions, shifting from congruent evaporation in the form of NIP under Langmuir conditions (open surface) to primary evaporation in the form of decomposition products under equilibrium conditions (Knudsen cell).

Adrenocorticotropic hormone-producing pheochromocytoma: A case report.

Introduction: Cases of ectopic production of adrenocorticotropic hormone are considerably rare, but persistent in clinical practice. Extremely rare cases of ectopic production, such as via pheochromocytoma secretion, require special clinical attention and prior knowledge. It is important to understand the diagnostic algorithm for identifying ectopic sources of adrenocorticotropic hormone production.