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.