What is the purpose of proper filter handling and chain-of-custody in PM sampling?

• A. To speed up sampling.
• B. To prevent contamination, ensure correct sample identification, and preserve sample integrity.
• C. To reduce the need for QA/QC.
• D. To minimize the need for calibration checks.

Answer: (B)

Preserving PM sample integrity and clear traceability through handling and documentation is what this is about. The filter is where the particulate matter is collected, so any improper handling can introduce contamination or damage the filter, changing the measured mass or composition. Using clean gloves, clean tools, and proper packaging, labeling, and storage keeps the sample representative of the air and protects it from moisture or other interference. Chain-of-custody provides a documented, time-stamped record of every transfer of the sample, ensuring its identity isn’t lost or swapped and that there’s a defensible history from collection to analysis. In regulatory or QA/QC contexts, this traceability is essential for data credibility and integrity. So, the purpose is to prevent contamination, ensure correct sample identification, and preserve sample integrity throughout the process.