2-WAY CONVERSATION WITH A MASS-SPECTROMETER - NONDESTRUCTIVE INTERACTIVE MASS-SPECTROMETRY

Most mass spectrometers employ destructive detection, so that it is ne cessary to repeat an experiment in order to vary even one parameter, I n contrast, Fourier transform ion cyclotron resonance mass spectrometr y offers non-destructive detection, so that ions remain available for further manipulation and redetection, Here, we show for the first time how to perform mass spectrometry interactively. Following each elemen tary experimental stage, such as ion generation, isolation, dissociati on, or detection, the operator is free to choose and tailor the next s tage without creating a fresh supply of ions, For example, we can test the effect of varying one parameter over several values without havin g to repeat the entire experimental event sequence each time, much lik e varying one letter or word in a sentence without having to rewrite t he whole sentence, Such interactive control promises to speed developm ent of complex experimental event sequences, as for optimizing the seq uencing and structural analysis of tiny amounts (e.g., femtomoles or l ess) of biomacromolecules (peptides, nucleic acids, oligosaccharides).