Which statement about detection limits in IH sampling is true?

• A. It defines the smallest amount that can be reliably detected, influencing compliance decisions.
• B. It represents the maximum measurable concentration.
• C. It is independent of calibration.
• D. It determines sampling duration

Answer: (A)

In IH sampling, the detection limit reflects how sensitive the measurement method is to a contaminant. It’s the smallest amount that can be reliably detected given the instrument’s noise, the sample matrix, and how the method is calibrated. This matters for compliance decisions because if a contaminant’s concentration is at or below that limit, you may not have a confident positive detection, even if some exposure exists. The detection limit is not the maximum measurable concentration—that would be the upper end of the method’s calibrated range. It also isn’t independent of calibration; calibration and method setup help establish how low you can reliably detect, since blanks, standards, and instrument performance all influence it. And it doesn’t by itself set how long you sample; sampling duration is chosen to collect enough material for detection, though a lower detection limit can influence how long you need to sample to reach a detectable signal.