| 摘要 |
A method is disclosed for the processing and preparation of a sample of one or more nonvolatile or thermally labile molecules for mass spectral analysis which comprises providing a solution of such molecules dissolved in a solvent, freezing the solution of dissolved molecules to form a frozen solution, and exposing the frozen solution to a source of energy to desorb the molecules to be analyzed from the surface of the frozen solution. The desorbed molecules may be photoionized after desorption, if necessary, and then conventionally analyzed in a mass spectrometer. The method mitigates or minimizes possible fragmentation or clustering of such large molecules during desorption from the frozen sample as well as providing a more reliable and uniform desorption. If desired the desorbed molecules may be subjected to a separate and controlled fragmentation step prior to entering the final mass spectral anslysis zone. The method may be interfaced with liquid chromatography equipment. |
