氧化硅介孔材料在基质辅助激光解析飞行时间质谱分析有机小分子中的应用

Application of Modified Mesoporous Silica Materials for Analysis of Small Molecules by MALDI-TOF-MS

研究了表面修饰的无机有机复合型介孔材料SBA-15-NA(1,8-Naphthalimide)作为基质在MALDITOF-MS分析中的应用。采用1,8-萘酰亚胺修饰SBA-15,1,8-萘二甲酸酐先与3-三甲氧基硅基-1-丙胺反应,得到的产物再修饰到SBA-15,得到SBA-15-NA,应用修饰后的介孔材料SBA-15-NA为基质获得了具有背景离子干扰少、离子化效率高、更高的峰值强度等优点的谱图。甲醇作为溶剂,分析物和基质的浓度比例为1∶10,采用以样品和基质等体积混合均匀点样方法,对低糖类、氨基酸类、植物激素生物代谢物和药物等不同结构的小分子化合物(分子量小于500)进行了MALDI-TOF-MS分析。在此优化的条件下得到了低检出限1×10-9g/L(亮氨酸,信噪比为5)和高重现性(≤30%)。采用衍生化的复合型介孔材料直接测定了实际尿样。

Mesoporous silica SBA-15 with a small organic molecular （1,8-Naphthalimide） was synthesized and used as matrix for MALDI-TOF-MS （Matrix-assisted laser desorption/ionization time of flight mass spectrometry） analysis. A modified SBA-15 matrix, SBA-15-NA （1,8-Naphthalimide） was synthesized by covalently attaching SBA-15 to an 1, 8-naphthalimide formed by 1, 8-naphthalic anhydride and 3-（trimethoxysilyl）propylamine. The mass spectra obtained with SBA-15-NA exhibited less background interference ions, higher desorption/ionization efficiency, and higher peak intensity. The matrix was initially prepared in methanol and mixed with analyte at a 1：1 volume ratio in vial. The solution of mixture was at a 10 ： 1 concentration ratio of matrix/analyte on a stainless steel target and allowed to air dry. The method was used to analyze various types Of low molecular weight （less than 500 ） chemical compounds such as monosaccharides, amino acids, phytohormones, drugs. Under the optimal conditions, it gave low detection limit of 1×10^-9g/L （Leucine, S/N=5 ） and good reproducibility （ ≤30% ）. The modified mesoporous silica materials have been employed in the urinary study for direct detection of metabolites.