What is hold time in sample handling?

• A. The maximum time allowed before analysis; exceeding it can degrade sample integrity and bias results.
• B. The time taken to collect a sample.
• C. The time required to calibrate the instrument.
• D. The time to transport samples to the lab.

Answer: (A)

Hold time is the maximum amount of time you can wait between collecting a sample and analyzing it to ensure the sample stays representative. If you exceed this window, the analyte can degrade, volatilize, or transfer to or from the collection medium, which biases the results. This concept is about preserving sample integrity during the period from collection to analysis, not about how long collection takes, how long calibration takes, or how long transport takes. Following the hold-time specification from the method or regulatory guidance keeps results accurate.