Every batch is tested by an independent laboratory for identity and purity, and the certificate is published before the order ships. Sold for laboratory research use only.
How much of the vial is the compound named on the label. The sample is separated into its components and the main one is measured against everything else. A higher percentage means fewer impurities.
A batch-specific laboratory document confirming identity and purity. Explain which labs test your batches and how a buyer matches a vial to its certificate.