Overview
Quality Control (QC) provides the confidence necessary to interpret experimental results. Implementing QC measures for incoming and internal reagents helps prevent experimental failure caused by 'bad' chemicals.
A successful QC program focuses on three main areas: identity verification, purity analysis, and documentation. Even simple visual or physical checks contribute to a robust QC strategy.
Key Concepts
Identity Verification
Always verify that the compound received matches the certificate of analysis. This includes checking appearance, checking physical states, and utilizing basic identification methods like infrared spectroscopy or melting point analysis where possible.
Purity Assessment
Purity is rarely 100%. Use analytical techniques like HPLC or GC to determine the purity profile of a substance. Knowing the impurities is often as important as knowing the primary component for experimental design.
Batch Tracking
Every compound should have a unique batch ID. If an experiment yields anomalous results, having clear records of which batch was used allows for retrospective analysis of whether the reagent itself was at fault.
Standardization
Establish a written 'standard operating procedure' (SOP) for QC checks. This ensures that the same metrics are applied to every reagent, creating a consistent baseline for experimental quality.
Practical Application
When a new shipment arrives, perform an initial inspection immediately. File the certificate of analysis with your internal records and assign an internal ID code to the batch.
Conduct regular re-testing of reagents, especially those that are known to be unstable over time. If a batch fails a QC check, quarantine it immediately to prevent accidental use in critical research.
Sources
- USP <1079> Good Storage and Distribution Practices
- Analytical Chemistry: An Introduction (Skoog)
- Journal of Pharmaceutical and Biomedical Analysis
Disclaimer: This content is for laboratory research use only. Not for human use or clinical applications.