Bioequivalence and Bioavailability Forum

Dear Najat!

❝ ❝ That’s the reason one should always inspect all chromatograms and go with a manual integration if the automatic one obviously failed.

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❝ Does this mean that all the chromatograms within a run should have the same integration mode (e.g. base to base) and if any chromatograms were integrated with a different mode (e.g. valley) within the same run they should be manually re-integrated to the (base to base) mode?

No. The analyst should visually inspect all chromatograms. For a particular chromatogram the automatically changed integration mode may be ‘correct’; in such a case leave it as it is. Only if the automatic integration obviously failed (this may happen quite often in the lower signal range where a lot of noise is present) the analyst should set the baseline manually. Most analysts I know would simply draw the new baseline with the mouse, rather than change integration parameters a couple of times until the system comes up with a better integration (this would result in a lot of trial-and-error…). If you change the integration parameters for the entire batch, you would again have to inspect all chromatograms, and repeat this cycle maybe forever…