Electrospray ionization interface to high pressure mass spectrometry and related methods
摘要
說(shuō)明書(shū)
The terms “miniature cylindrical ion trap”, “miniature CIT” and “mini-CIT” refer to a cylindrical ion trap “CIT” with a critical dimension that is in the millimeter to submillimeter range, typically with associated apertures in one or more electrodes of the ion trap having a critical dimension between about 0.001 mm to about 5 mm, and any sub-range thereof. The ion trap electrode central aperture can take on different geometries such as a cylindrical or slit shaped void and arrays of voids are possible.
The term “microfluidic chip” is used interchangeably with “microchip” and refers to a fluidic sample processing device with sub-millimeter sized fluidic channels with at least one integrated emitter for processing samples.
Mass spectrometry has historically been performed under conditions of high vacuum. The reason for this condition is that performance is enhanced if ions do not collide with background gas molecules during their trajectory from an ion source through a mass analyzer arriving at a detector. Ion-molecule collision events scatter the ions away from their intended trajectory, often degrading mass resolution and signal strength. The vacuum that achieves sufficient resolution in conventional systems can be formalized through the Knudsen number, Kn. Mass spectrometry is typically performed in the molecular flow regime defined as Kn>1, and in conventional practice, Kn is between about 100 and over 10,000 for mass analyzers of mass spectrometers.
