- GC profile
- Gas chromatography of limonene, myrcene, decanal, octanal, linalool and other markers against the specification.
- Physical constants
- Specific gravity, refractive index and optical rotation at a stated temperature, compared with the supplier's specification or the Food Chemicals Codex monograph where one exists.
- Aldehyde content
- Total aldehydes as decanal, by titration or GC, the main grading value for orange oils.
- Appearance and odor
- Color, clarity and odor against a retained standard; off-notes often show up before the GC profile shifts.
- Heavy metals
- Lead and arsenic, typically by ICP-MS, against the supplier's specification.