Repeat analysis and re-injection of samples [Bioanalytics]
Kindly give your suggestions on what steps should be taken when some subject samples in an analytical run have poor chromatograms such as peak split, peak shoulder, etc. The curve and QC all pass acceptance criteria with good chromatograms. Most samples also have good chromatograms. After studying the LC pressure, it was found that samples with poor chromatograms have abnormal LC pressure (swing, fluctuate). Currently, we do not have the strategy written in our SOP to handle this kind of situation. Since we think this is instrument issue, we have decided to reject the run and reanalysis the whole batch (please comment).
Please also give your comment on what should be done (investigation steps, reinjection, reanalysis, etc) if this kind of event happens again.
Edit: Category changed; see also this post #1. [Helmut]