Which statement best describes the role of chain-of-custody documentation in sampling?

• A. Documentation of sample handling from collection to analysis.
• B. Using only one sample.
• C. Not labeling samples.
• D. Relying on memory.

Answer: (A)

In sampling, the key idea is to keep a complete, verifiable record of every step a sample takes from collection all the way through analysis. This means documenting who handled the sample, when it was collected, where it has been stored or transported, any transfers between people, and how it was preserved. That chain-of-custody record protects the sample’s identity and integrity, helps prevent contamination, and provides a trustworthy trail for QA and regulatory or legal purposes.

So the best description is documenting how the sample is handled from collection to analysis. Without this documentation, a sample’s history is uncertain, which can lead to mix-ups, questions about reliability, and trouble if results need to be reviewed or defended.

The other ideas don’t fit because they don’t establish traceability: using only one sample ignores the need to track all handling steps; not labeling samples destroys the ability to identify and follow a sample through the process; relying on memory leaves no verifiable record, making it easy to lose track of who did what and when.