What defines a blank sample in this sampling protocol?

What defines a blank sample in this sampling protocol?

• A. New, unused wipe tested for contamination
• B. Used wipe previously in contact with a surface
• C. Wipe used for cleaning surfaces
• D. Wipe from a field sample

Answer: (A)

A blank sample is a control used to detect contamination that can be introduced during the sampling process itself. For wipe sampling, the proper blank is a new, unused wipe that has not touched any surface and is subjected to the same handling and analysis steps as real samples. This lets you see if the wipe, packaging, lab reagents, or handling added any contaminant before you ever test actual surfaces. If the blank shows contamination, it signals that some part of the process could be introducing lead and you’d interpret real sample results with that background in mind. The other options describe wipes that have already contacted surfaces or been used for cleaning, which would not serve as a background check and could carry actual sample material.

A blank sample is a control used to detect contamination that can be introduced during the sampling process itself. For wipe sampling, the proper blank is a new, unused wipe that has not touched any surface and is subjected to the same handling and analysis steps as real samples. This lets you see if the wipe, packaging, lab reagents, or handling added any contaminant before you ever test actual surfaces. If the blank shows contamination, it signals that some part of the process could be introducing lead and you’d interpret real sample results with that background in mind. The other options describe wipes that have already contacted surfaces or been used for cleaning, which would not serve as a background check and could carry actual sample material.