2.10.2 TOC
The most dramatic impact on the TOC of a solution during sample storage is from organic residues leaching from the container or closure surface. If reusable containers are used for TOC sampling, then the risk of leachable residues is much greater than if single-use certified low-TOC sample containers are used. Refrigeration may slow this rate of leaching. If certified low-TOC containers are used, only that certified amount of TOC will leach into the sample fluid no matter how long it is stored. However, prolonged storage can lead to alteration (based on surface adsorption/desorption or microbial consumption) of the soluble TOC interaction with the container, hence extended storage should be supported by a risk analysis and supporting data.