AssayIndex
Physical

Headspace oxygen

Oxygen in the gas space above the product. Correlates with sulfoxide content and is essentially never measured.

Related terms

Oxidation
Addition of oxygen. Methionine to sulfoxide (+15.995) then sulfone (+31.990); tryptophan to oxindole and beyond; cysteine to sulfonic acid.
Closure integrity
Whether the stopper and crimp maintain the container's seal and vacuum. A failure lets in moisture and oxygen.

Where this term appears

The glossary exists to make record pages readable without a chemistry degree. Every technical term on a report resolves here.