Spectrus: Evaluating component stability over time using overlayed chromatograms

Description
Stability studies often generate multiple xC/UV/MS chromatograms for the same sample stored under different conditions or time points. Spectrus overlays help visualize appearance/disappearance of peaks over time.

Solution

1. Acquire xC/UV/MS runs for the same sample at multiple time points and/or storage conditions.
2. Import all relevant chromatograms into Spectrus.
3. Overlay chromatograms and align chromatograms of different datasets by:
   • Setting Display as tile and selecting vertical stacking icon
   • Selecting both chromatograms while holding shift (window titles will appear gold) and selecting Synchronize
4. Align traces using Retention time (if stable) or reference peaks or markers (if small shifts occur) by:
   • Selecting a desired chromatographic trace by clicking on it (trace will appear red)
   • Adjusting the Detector Lag value so traces are aligned
5. Examine:
   • Decrease in the main component peak area over time.
   • Appearance and growth of degradation peaks.
6. Quantify changes:
   • Integrate relevant peaks at each time point.
   • Export peak areas to a table for further kinetic or trend analysis.
7. Include select overlay plots and tables in stability reports to illustrate trends.