Each analytical method specifies a required preservative to prevent chemical changes in the sample between collection and analysis. The preservative on a SampleBottle documents what was added — common examples include "HCl" for metals, "H2SO4" for nitrogen species, and "none/unpreserved" for certain biological parameters. Recording the correct preservative in Piper is essential: an incorrect or missing preservative can cause result rejection or require the regulator to discount the data. The laboratory also verifies preservative on receipt.
Technical section
Data model, API, and internals — visible to developers.