Blanks samples are used to test two conditions: whether the media is contaminated and whether the sampling technique was performed properly. Which statement about blanks samples is true?

Blanks samples are used to test two conditions: whether the media is contaminated and whether the sampling technique was performed properly. Which statement about blanks samples is true?

• A. They test whether the media is contaminated and whether the sampling technique was performed properly
• B. They measure the lead concentration on dust
• C. They calibrate laboratory instruments
• D. They assess the weather conditions during sampling

Answer: (A)

Blanks are quality-control samples used to catch contamination from the sampling media and to verify that the sampling procedure was carried out correctly. Because blanks are designed to contain no target material, any detected lead in a blank points to contamination introduced during sampling, handling, or laboratory processing. This dual role helps ensure that results from real dust samples reflect true environmental levels rather than artifacts of the sampling method or media. It’s this ability to reveal both media contamination and procedural issues that makes blanks the best choice. They aren’t used to measure lead concentration in dust, which comes from actual samples; they aren’t calibration standards for instruments; and they don’t assess weather conditions during sampling.

Blanks are quality-control samples used to catch contamination from the sampling media and to verify that the sampling procedure was carried out correctly. Because blanks are designed to contain no target material, any detected lead in a blank points to contamination introduced during sampling, handling, or laboratory processing. This dual role helps ensure that results from real dust samples reflect true environmental levels rather than artifacts of the sampling method or media. It’s this ability to reveal both media contamination and procedural issues that makes blanks the best choice. They aren’t used to measure lead concentration in dust, which comes from actual samples; they aren’t calibration standards for instruments; and they don’t assess weather conditions during sampling.