Abstract: A titanium-incorporated SBA-15mesoporous material (Ti-SBA-15) was synthesized via the co-condensation of tetraethyl orthosilicate (TEOS) and tetrabutyl titanate using surfactant P123 as the template. Due to the existence of Ti in the framework of SBA-15, the synthesized Ti-SBA-15 was applied as the selective adsorbent of phosphopeptides from the complex tryptic digest of β-casein. The matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis showed that the phosphopeptides of β-casein digest could be selectively enriched by the Ti-SBA-15 with Ti/Si molar ratio of 0.08, even under the interference of bovine serum albumin (BSA) with the molar ratio of β-casein to BSA up to 1:100. It can be concluded that the Ti-SBA-15 showed the specific adsorption toward the phosphorylated peptides, which provides great potential in the specific capture of phosphopeptides.

Key words: matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) , phosphopeptides, selective enrichment, titanium-incorporated SBA-15 mesoporous material (Ti-SBA-15)