Which component is essential to ensure data integrity from sample collection to reporting?

• A. Weather records
• B. Chain of custody
• C. Plant location map
• D. Equipment calibration schedule

Answer: (B)

Maintaining a verifiable trail of who handled a sample at every step from collection through reporting is essential for data integrity. This is achieved through the chain of custody, which records who collected the sample, all transfers, where it was stored, and when each handoff occurred. By documenting every movement and access, it becomes possible to confirm that the sample in the final report is the same one that was originally collected, has not been swapped or altered, and has not been tampered with. This transparency builds trust in the data and provides a defensible link between the sample and the results.

Context helps: while weather records can describe conditions at the time of collection and a plant location map aids interpretation, neither guarantees that the sample’s handling and transfers were properly tracked. Equipment calibration schedules are important for measurement accuracy, but they don’t establish who handled the sample or how it was moved and stored through the process. The chain of custody directly addresses the integrity of the sample’s journey from start to finish.