Watch a MALDI Spectrum Grow

This animation shows the sequence of 9 laser shots fired on a single spot of a MALDI target and finally the labeling of the peaks. It repeats four times. The signal at m/z 1347.7 represents the [M+H]+ peak of the small peptide substance P. It is accompanied by its isotopic peaks. Matrix CCA, positive-ion reflector mode. The spectrum has been obtained from our Biflex after installation of PIE.

MALDI spectrum appears

PS:
MALDI and FAB are sometimes referred to as "energy-sudden methods" because energy for desorption/ionization is transferred to a relatively small target area during a really short time span. Typical duration of a UV laser pulse is 3 ns. While there is only one single event in MALDI, under FAB conditions this happens around thousand times per microsecond and each impinging particle causes a single event for a hundred of molecules. In the end, both methods generate a small-sized plasma plume.
Do you need some help for your imagination? Yes (1.1MB Quicktime movie).

08 June 2005