Sample Presentation Apparatus for Mass Spectrometry

The use of matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometer probe devices which actively participate in the chemical or enzymatic characterization of an analyte. The primary function of current probe devices is that of a sample holder--the device is only used to introduce sample into the mass spectrometer. The "active" probe devices still act in this capacity, however, prior to insertion into the mass spectrometer the probe devices perform chemical or enzymatic modifications to the analyte. After time is given for the reaction to proceed, the "active" probe device is inserted directly into the mass spect- rometer and the results of the chemical or enzymatic modification monitored.