How to analyze MALS data

All analysis uses ASTRA (Wyatt’s software for SEC in-line MALS). At the beamline, we use ASTRA 7.

  • Open an experiment (your file)
  • Open Experiments tab on the bottom left
  • Configuration -> generic pump (on left side panel)
    • Set flow rate, (default is 0.8 but you should remember to change this to the real flow rate for any given experiment).
  • Procedures -> baselines (on left)
    • First click autofind baselines
    • Click through baselines and make sure all baselines are defined (if they are not good you have to define them; click once at start point and, hold and drag it to right side to define the baseline and range)
    • Click Apply
  • In the top toolbar, Experiment -> configuration -> band broadening
    • Define an area
    • Click Perform fit
    • Manually define peaks if needed
    • Click Apply
  • Click Peaks on left side panel
    • Choose what peaks (UV curve) you will be working with (better to choose range above baseline)
    • Click Apply
  • Click Molecular Mass & Radius from LS on left side panel
    • De-select detectors that had bad baselines
    • Click Apply
    • Can scroll through peaks to see MW for each peak from MALS
  • Click Rh from QELS on left side panel
    • Can scroll through peak and see Rh from QELS (DLS)