Desorption-ionization mass spectrometry with porous silica gel and its derivatives as matrix

Porous silica gel and its derivatives have been applied as matrix for the a nalysis of small molecules. In contrast to the conventional MALDI-TOF MS, t he signal interference of low-molecular analytes by the matrix has been eli minated in the MALDI-TOF MS with porous silica gel and its derivatives as t he matrix. The detection of limit by this method reached the fetomole level s, and almost no fragment of the analytes has been observed. The porous str ucture of silica gel is essential for effective desorption and ionization o f the analytes. Among several different types of silica gel, the silica gel with the pore size of 30 nm gives the best signal. The analyte penetration into the pore is very important. Matrix agents of DHB and CCA have been co valently bound to silica gel for the improvement of the intensity of the sp ectrum signal.