Sensitivity improvement in hydrophilic interaction chromatography negative mode electrospray ionization mass spectrometry using 2-(2-methoxyethoxy)ethanol as a post-column modifier for non-targeted metabolomics☆

Add time:08/20/2019    Source:sciencedirect.com

The application of ammonia acetate buffered liquid chromatography (LC) eluents is known to concomitantly lead to ion suppression when electrospray ionization mass spectrometry (ESI–MS) detection is used. In negative ESI mode, post column infusion of 2-(2-Methoxyethoxy)ethanol (cas 111-77-3) (2-MEE) was shown in the literature to help to compensate this adverse effect occurring in reversed phase liquid chromatography mass spectrometry (RP-LC–MS) analyses. Here a setup of direct infusion and hydrophilic interaction chromatography (HILIC) post-column infusion experiments was established in order to investigate systematically the beneficial effects of 2-MEE. We demonstrate that, 2-MEE can help to improve ESI–MS sensitivity in HILIC too and reveal analyte structure specific behaviors. Our study indicates that 2-MEE especially improves ESI response for small and polar molecules. The ESI response of stable isotope labeled amino acids spiked into biological matrices increases up to 50-fold (i.e. D5-l-glutamic acid) when post column infusion of 2-MEE is applied. A non-targeted analysis of a pooled urine sample via HILIC–ESI–QTOF–MS supports this hypothesis. In direct infusion, the combined application of an ammonia acetate buffered solution together with 2-MEE results in an improved ESI response compared to a non-buffered solution. We observed up to 60-fold increased ESI response of l-lysine. We propose this effect is putatively caused by the formation of smaller ESI droplets and stripping of positive charge from ESI droplets due to evaporation of acetic acid anions. In summary, post-column infusion of 2-MEE especially enhances ESI response of small and polar molecules. Therefore it can be regarded as a valuable add-on in targeted or non-targeted metabolomic HILIC–MS studies since this method sets a focus on this molecule category.

We also recommend Trading Suppliers and Manufacturers of 2-(2-Methoxyethoxy)ethanol (cas 111-77-3). Pls Click Website Link as below: cas 111-77-3 suppliers

Prev:Adsorption of hydraulic fracturing fluid components 2-Butoxyethanol (cas 111-76-2) and furfural onto granular activated carbon and shale rock
Next:Short communicationProcedure for the quantification of the biomarker (2-methoxyethoxy)acetic acid in human urine samples)