Interfaces To Connect Thin-Layer Chromatography with Electrospray Ionization Mass Spectrometry

Abstract

This study has developed two interfaces to connect small-size thin-layer chromatography (TLC) with electrospray ionization mass spectrometry (ES-MS) for the continuous analysis of organic mixtures. The interfaces are (1) two bound optical fibers inserted into the C18-bonded particles at the exit of a small TLC channel and (2) a small commercial TLC strip with a sharpened tip. A reservoir continuously supplied a makeup solution to the tip of the TLC channel. The high voltage required for electrospray ionization was introduced into the makeup solution or mobile phase through a Pt wire, and electrospray was generated at the tip of the bonded optical fibers and at the sharp end of the TLC strip. Since small-size TLC channels were used, the elution time was short and less than 0.2 microL of the sample solution and 200 microL of the eluting solvent were required. Organic mixtures were separated successfully and detected on-line using the TLC/ES-MS techniques.

Analytical Properties of Solid-substrate Electrospray Ionization Mass Spectrometry

“…When methanol, a solvent that favored elution of proteins, was used as the solvent, lysozyme signals were detected with low salt interferences ( Figure S2b). However, such large molecules were found to have difficulty being carried through and detected if they were loaded too far away from the tip cusp, similar to the observation in TLC [28,29].…”

Comparative TOF‐SIMS and MALDI TOF‐MS analysis on different chromatographic planar substrates

“…For comparison, the TOF-SIMS detection limits of adsorbed proteins were investigated on four model substrates: mica, poly(tetrafluoroethylene), allyl amine plasma, and heptyl amine plasma polymer. in this study [28]. MALDI TOF-MS detection limits for AA and GA in this experiment were not established.…”

“…Raman spectroscopy layer a monolithic silica a SIMS-interfacing modified Si 60 layer (5) while in the positively charged ion macroscan the order changed [28]:…”

“…It was observed that secondary ion yield enhancement also depends on the time of analysis. Some secondary ions show a visible intensity improvement after 5 days, while for other signals the increase occurs no earlier than after 14 days or more [28]. Obtaining characteristic fragments of molecular species requires improvement in postimpact ionisation or use of another (bismuth, gallium, polyatomic) primary ion gun and production of high resolution spectra.…”

“…TOF-SIMS preliminary AA LOD was determined at value of 19.9 ng (substrate B). The LOD for both AA and GA on silver substrate were determined at 1 ng and 4 ng, respectively [28]. For comparison, the TOF-SIMS detection limits of adsorbed proteins were investigated on four model substrates: mica, poly(tetrafluoroethylene), allyl amine plasma, and heptyl amine plasma polymer.…”