Protein UTLC-MALDI-MS using thin films of submicrometer silica particles

Abstract

Slides for ultra thin-layer chromatography (UTLC) were made by coating nonporous silica particles, chemically modified with polyacrylamide, as 15μm films on glass or silicon. Three proteins, myoglobin, cytochrome c and lysozyme, are nearly baseline resolved by the mechanism of hydrophilic interaction chromatography. A plate height as low as 3μm, with 3900 plates, is observed in 14 mm. Varying silica particle diameter among 900, 700 and 350. nm showed that decreasing particle diameter slightly improves resolution but slows the separation. Matrix-assisted laser desorption/ionization (MALDI)-MS of the proteins after separation is demonstrated by wicking sufficient sinapinic acid into the separation medium. © 2011 Elsevier B.V.