Sample Hold Times: Why They Matter and How to Manage Them
Posted on : December 4, 2025
Sample Hold Times: Why They Matter and How to Manage Them
Sample holding times are maximum intervals between collection and analysis during which samples remain valid. Exceeding hold times invalidates results and may require recollection.
Why Hold Times Exist
Environmental samples change over time. Volatile compounds evaporate. Bacteria grow or die. Metals adsorb to container walls. Hold times represent the window during which these changes remain within acceptable limits.
Common Hold Times
- Chlorine residual: Immediate analysis
- Volatile organics: 14 days with preservation
- Metals: 6 months with acid preservation
- Nitrate: 48 hours to 28 days
Managing Hold Times with LIMS
LIMS automates hold time management by calculating expiration dates, displaying remaining time on worklists, alerting analysts when samples approach limits, and preventing result entry for expired samples.
