- Identity (HPTLC)
- Fingerprint against a Prunus africana bark reference.
- Phytosterol assay (GC)
- Total phytosterols, mainly beta-sitosterol, by GC or HPLC against the spec.
- Residual solvents
- For extracts made with ethanol or other solvents, residual solvent levels against USP <467> or the buyer's spec.
- Heavy metals
- Lead, arsenic, cadmium and mercury, usually by ICP-MS, checked against the buyer's limits and Prop 65 exposure targets where relevant.
- Microbiology
- Total plate count, yeast and mold, E. coli and Salmonella. Raw herb powders carry more microbial load than extracts and may be steam treated, which should be stated on the COA.
- Physical tests
- Appearance, loss on drying and, for oil extracts, peroxide value.