Fig. 2.

(a) Protonated d-tryptophan data at m/z 205.0977 Da. As seen in the raw data, as the DTIMS electric field decreases the arrival time of the ions increases. (b) Ions were tracked by PIXIE using global data association. The optimal association hypothesis consisted of a single ion path. This association hypothesis had an a posteriori probability higher than all other association hypotheses and was thus chosen to explain the observed peaks. Other peaks failed to meet the criteria for identification of the target ion and were thus registered as artifacts. Based on the optimal association hypothesis, a single conformer was reported for the target m/z with a CCS value of 154.44 Å²