This blog post focuses on the unprocessed, processed, and re-processed chromatographic data (e.g., data generated using chromatographic instruments such as High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC), Ultra Performance Liquid Chromatography (UPLC), etc.).

To some operators, the unprocessed chromatographic data might not be recognized, nor would they raise any concerns with the validity of the results reported to release product or to support regulatory filings. However, to ensure the integrity of reported results, all data should be identified, accounted for, and/or investigated whether they were processed or unprocessed.

To properly and consistently integrate chromatographic data, laboratories should have documented procedures providing instructions on: (1) how to process chromatograms; (2) when chromatograms can be reprocessed; (3) the different types of chromatographic data processing (manual integrations vs. automatic integrations); and (4) instructions on the required documentation and management’s prior approval on reprocessing and manual integrations.

Most laboratories have procedures describing how to process and reprocess chromatograms. However, not all laboratories properly define manual integration. Some laboratories consider chromatograms to be manually integrated only if analysts physically draw a baseline using the “drag and drop” functions, while multiple processing methods and/or multiple processing method versions used to integrate different samples within an injection sequence are not considered as manual integrations as these methods and method versions integrate the peak by the system.

It is important to know that within an injection sequence, whether the “drag and drop” function or different processing methods and/or different processing method versions are used, these are considered manual integrations as not all chromatograms within the injection sequence are integrated using the same integration parameters. As such, they should only be used with proper documented justification and prior management approval. It is also important to know that regulatory agencies have historically raised concerns with the integrity of chromatographic data when observing manual integration practices.

If your firm has questions regarding the handling of chromatographic data, Lachman can help! Please reach out to us at to schedule a consultation.