標題: | Laser desorption/ionization time-of-flight mass spectrometry on sol-gel-derived 2,5-dihydroxybenzoic acid film |
作者: | Lin, YS Chen, YC 應用化學系 Department of Applied Chemistry |
公開日期: | 15-十一月-2002 |
摘要: | This work presents a novel method for direct desorption/ ionization of analytes from sol-gel-derived film. 2,5-Dihydroxy benzoic acid (DHB), a common MALDI matrix, was incorporated into a sol-gel polymeric structure. The sol-gel-derived DHB thin film can assist the mass analysis of analytes by laser desorption/ionization, with a matrix interference-free background in the mass spectra. The sol-gel-derived film can function as an energy absorber during laser irradiation because it contains DHB molecules. Furthermore, laser irradiation with normal laser power (70 -110 muJ) is not likely to generate any background ions from this sol-gel-DHB derived film. The samples were prepared straightforwardly. After a thin film was formed on a Parafilm membrane from the sol-gel-derived DHB solution coating, the sample solution was directly added to the top of the film, for laser desorption/ ionization mass analysis. The analyte signals were homogeneously obtained on the sol-gel-derived DHB film. Experimental results show that the optimum concentrations of DHB incorporated in the sol-gel solution were between 7500 ppm and 10 000 ppm, providing a matrix interference-free background. Analytes, including small proteins, peptides, amino acids, and small organics, were used to demonstrate the effectiveness of the proposed method. However, a higher laser power (> 110 muJ) than normal was required to desorb small proteins from the sol-gel-derived DHB film. Therefore, a few matrix ions desorbed from the thin film were generated during laser irradiation. The detection limit for both small molecules and proteins, using this sol-gel-assisted laser desorption/ ionization (SGALDI) mass spectrometry (MS), was as low as 81 fmol. However, a mass spectrometer with cutoffmass selection could detect 8.1 fmol of cytochrome c. The largest analyte observed by the SGALDI-MS in this study was myoglobin. |
URI: | http://dx.doi.org/10.1021/ac020418a http://hdl.handle.net/11536/28381 |
ISSN: | 0003-2700 |
DOI: | 10.1021/ac020418a |
期刊: | ANALYTICAL CHEMISTRY |
Volume: | 74 |
Issue: | 22 |
起始頁: | 5793 |
結束頁: | 5798 |
顯示於類別: | 期刊論文 |