Nano‐liquid chromatography—direct electron ionization mass spectrometry: improving performance by a new ion source adapter

Abstract

A novel interface adapter has been designed to provide a new way of directly coupling a nano-liquid chromatograph to an electron ionization mass spectrometer. It connects the transfer capillary coming from the liquid chromatograph to the ionization chamber and can be easily screwed into the ion source. Liquid coming from the column passes through the heated adapter flow path and is vaporized. A continuous flow of new liquid pushes the vapor into the ionization chamber where it is ionized and continues on to the mass analyzer. The advantages of the new adapter are reduced ice formation inside the ion source and less clogging of the transfer capillary. Improvements achieved are demonstrated on the basis of caffeine and steroid analysis. The limits of detection of selected steroids are compared with and without the adapter. The adapter improves the detection limit of the system by a factor of 2 and precision from ≤15% to ≤9% relative standard deviation. No derivatization procedure is necessary before the analysis of small polar compounds. The resulting spectra are reproducible, easily interpretable, and database searchable. The new method is robust, delivers reproducible results, and provides a highly efficient alternative to existing methods in the field of pharmaceutical analysis.

Further exploring the absorption and enterocyte metabolism of quercetin forms in the Caco-2 model using nano-LC-TOF-MS

“…C). Some studies suggest that peak tailing could be due to interactions with the C18 layer , the presence of some residual silanols or the interface itself .…”

Direct Coupling of HPTLC with MALDI‐TOF MS for Qualitative Detection of Flavonoids on Phytochemical Fingerprints

“…One of the reasons is that TLC is a simple and substance‐preserving chromatographic technique where, in contrast to liquid chromatography (LC), after evaporation of the developing solvent the sample remains conserved in the silica stationary phase and can be used for further analysis. One strategy to couple TLC with MS involves the application of an interface in order to transfer a chosen zone on the silica plate by a solvent stream to an MS detector or LC–MS system (Hayen and Volmer, ; Rolli et al , ; Flender et al , ). The advantage of this interface is that the zone of interest can be extracted from the plate, collected and subjected not only to MS but also to other techniques such as NMR for structure elucidation, as recently demonstrated (Adhami et al , ).…”

Evaluation of a liquid electron ionization liquid chromatography–mass spectrometry interface

“…introduced a new interface adapter to minimize this issue [47,48], but the problem was never completely solved.…”