Simple and rapid removal of the interference in gangliosides extracted from HPTLC spot on MALDI-TOF MS analysis

Abstract

Extraction of thin-layer chromatography (TLC) spot with organic solvents is one of the convenient methods for glycolipid isolation from crude samples, but other background contaminants are also co-extracted during this process. Calcium sulfate (gypsum), starch and synthetic polymers are commonly used as binders in TLC plates, and the co-extracted synthetic polymers usually interfere with further structural analyses, especially in analysis by mass spectrometry (MS). Several column chromatographic processes are therefore used to purify these extracts. However, the purification processes are time consuming and suffer from sample loss. In our previous study, we established a method for detergent removal from glycolipids in a detergent-resistant membrane microdomain (DRM). The procedure is based on selective detergent extraction, in which the sample is dried in a glass tube, followed by washing with non-polar organic solvents, 1,2-dichloroethane (DCE). In this study, we have attempted to apply this method for the background removal from gangliosides and glycosylinositolphosphoceramides extracted from high performance TLC (HPTLC) spots. After DCE washing, these glycolipids were detected by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS, and it was found that DCE washing could effectively remove HPTLC backgrounds.

TLC-based MS Imaging Analysis of Glycosphingolipids and Glycerin Fatty Acid Esters after 1,2-Dichloroethane Washing

“…To suppress the background peaks in TLC-blot MSI, the removal of binders on the TLC plate would be required before blotting. In a previous study, we confirmed that DCE could remove the background from glycolipids scraped and recovered from the TLC plate [27][28][29] . We applied this method to remove the background from the TLC plate.…”

“…3A). Generally, calcium sulfate (gypsum), starch and synthetic polymers are used as binders in TLC plates; therefore, they are transferred to the PVDF membrane together as we described before 29 . To suppress the background peaks in TLC-blot MSI, the removal of binders on the TLC plate would be required before blotting.…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2013–2014

“…Calcium sulfate (gypsum), starch and synthetic polymers are commonly found as contaminants in GSL samples obtained by solvent extraction from TLC plates. In order to remove these contaminants, Kamimiya et al () have dried extracts (from chloroform/methanol/water) in a glass tube and simply washed several times with the non‐polar solvent, 1,2‐dichloroethane.…”

Scanning densitometry and mass spectrometry for HPTLC analysis of lipids: The last 10 years

“…Among organic revealing agents (Figure 1), orcinol (5-methylbenzene-1,3-diol) allows selective detection of sugar groups in GSL, PL, GL to be performed. [48,49] Lipids without sugar units give no response when using orcinol at 550 nm.…”