Glossary
Loss on drying (LOD)
A gravimetric test reporting the percentage of mass a sample loses when dried under defined conditions. It captures water and other volatile matter together, unlike a specific water determination such as Karl Fischer titration.
Why it matters on a certificate
Loss on drying is ubiquitous on certificates and easy to confuse with water content. The two are different tests with different limits; a certificate that swaps them, or reports one against the other's limit, produces a comparison that means nothing. The drying conditions belong on the document too, because the result depends on them.
A worked example
A monograph asks for water content by titration; the certificate reports "LOD: 0.4%" instead. The number may be honest, but it answers a different question from the one the claimed standard asked.
Examples are synthetic and illustrative; any limits shown are not the requirements for any particular material.
The COA Validator checks the element this term describes on every certificate it reads, and reports what is present, what is missing and what does not add up.