A hybrid ionic liquid–matrix material, [TiO2–Si–NH3+][CHC−], as a novel matrix for the analysis of small molecules by MALDI-TOF MS

• A hybrid ionic liquid–matrix material [TiO2–Si–NH3+][CHC−] was synthesized and used in the MALDI-TOF MS analysis for small molecules.
• The matrix material exhibited a good analyte signal intensity and a minimization of interference signals caused by matrix ions.
• A method of rapid detection of low molecular weight compounds by MALDI-TOF MS was developed.

A hybrid ionic liquid–matrix material ([TiO2–Si–NH3+][CHC−]) was successfully designed and applied as a novel matrix for the analysis of small molecules (<500 Da) by MALDI-TOF MS. [TiO2–Si–NH3+][CHC−] was obtained by covalently attaching an ionic liquid formed by α-cyano-4-hydroxy cinnamic acid (CHCA) and 3-APTES to the surface of TiO2. By immobilizing the ionic liquid on the TiO2, it was possible to avoid interference of matrix background ions and greatly improve the analyte signal intensity in the MALDI-TOF MS analysis. Using [TiO2–Si–NH3+][CHC−] as a matrix, we performed the analysis of various types of small molecules, including amino acids and dopamine. Compared with a conventional CHCA matrix, [TiO2–Si–NH3+][CHC−] exhibited a good analyte signal intensity and a minimization of interference signals caused by matrix ions. This was hypothesized to be due to the more efficient laser desorption and ionization facilitated by the new matrix material.

Figure optionsDownload high-quality image (146 K)Download as PowerPoint slide