Purpose: Preservation of samples is based on regulatory or method specific requirements with the intention of maintaining the sample in the same state as the time it was collected – this includes methanol preservation of soil samples. When collecting samples for volatile analysis, void space can impact the integrity of the sample and the associated results.
Preservative Tips:
- Where required by regulation, use methanol preservation for volatiles in soil
- If an unpreserved container is required however only preserved container is on-hand, rinse the container with DI water and additional sample
- Sulphide and Cyanide analysis in water require the preservative to stabilize the sample and cannot be completed accurately in samples collected without preservative
Void Space Tips:
- Do the “shake test” on soil samples – if you hear sample rattling in the jar, there is likely void space
- Turn over water vials to inspect for the presence of air bubbles
- Where possible, try to fill at least one jar with minimal void space. Indicate on the COC if void space is due to:
- Insufficient sample volume
- Frozen sample
- Sample texture/hardness