Analysis of organic reactions by thin layer chromatography combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
The products of a wide variety of organic reactions were rapidly identified by their masses through a combination of thin layer chromatography (TLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Crude mixtures of peptides and glycopeptides, complex carbohydrate reactions, and a classical organic reaction were analysed using the following standard protocol. The components of the reaction mixtures were first separated on the TLC plate, scraped off, extracted and analysed by MALDI-TOFMS. The technique used is easy and applicable to most organic reactions, becoming a very powerful technique in reaction optimization once composition and identity of TLC spots have been established by MS. Moreover, the TLC/MALDI-TOFMS method was used to identify low molecular weight compounds with masses within the matrix region (100-500 u), a goal which is normally difficult to achieve. We successfully detected low molecular weight compounds by suppression of the matrix peaks using a relatively low matrix:analyte ratio (15:1 or lower). Doping both matrix and analyte solutions with [Cs]+ ions resulted in suppression of both [Na]+ and [K]+ peaks, thus enhancing the spectral signals and making identification of low molecular weight compounds more facile.
St Hilaire
P M
PM
Carlsberg Laboratory, Department of Chemistry, Valby, Denmark.
Cipolla
L
L
Tedebark
U
U
Meldal
M
M
D002241:Carbohydrates / Q000737:chemistry; D002625:Chemistry, Organic / Q000295:instrumentation*; D002855:Chromatography, Thin Layer; D008670:Metals / Q000737:chemistry; D008968:Molecular Conformation; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002241:Carbohydrates; D008670:Metals; D010455:Peptides