Die kombinierte Anwendung von Gaschromatographie und Massenspektrometrie

Open split interface for capillary gas chromatography/mass spectrometry

“…Two alternatives exist at this time. First, the capillary GC column can be directly connected to the mass spectrometer source (1,2). This method has many advantages; however, it also has several disadvantages, including: (1) all of the sample, including solvent, elutes directly into the mass spectrometer source, and (2) changing columns is laborious and time consuming, as the mass spectrometer vacuum system is vented with each column change.…”

“…Some advantages of an open split interface include the following: (1) Capillary columns can be changed without an isolation valve or venting the mass spectrometer vacuum system. (2) The capillary column chromatography, in some modes of operation, is unaffected by the vacuum system. (3) The dynamic range of sample component concentrations can be greatly increased by purging portions of the highly concentrated sample, such as solvent components.…”

“…Some of these are as follows: (1) The interface body is completely inside the GC oven, improving accessibility, compared to interfaces housed in the heated interface oven. (2) The use of Pyrex glass allows precise visual adjustment of fused silica (FS) capillary columns and the interface tubing [FS or vitreous silica (VS), Superox-4 deactivated] (6, 7). (3) The interface tubing (0.15 mm i.d.)…”

“…By polarized infrared reflectance at oblique angles of incidence, infrared spectra of thin films on metals can be obtained. In 1959, following from the work of Fry (1), Francis and Ellison (2) reported that absorption-like spectra of films, which were as thin as a monolayer, could be obtained by the oblique multiple reflection of polarized infrared radiation from metal surfaces. Since that time, the characteristics of the technique, which is referred to in the literature as differen--tial-reflection or absorption-reflection spectrometry, have been studied in detail.…”

Adjustable open-split interface for gas chromatography/mass spectrometry providing solvent diversion and invariant ion source pressure

“…Various approaches to the interfacing of gas chromatographs to mass spectrometers have been described. Of those approaches which utilize fused-silica capillary columns, the most common is the direct connection of the capillary to the ion source (1,2). This approach has the advantage that no interface exists to possibly reduce chromatographic resolution.…”