What purity means.

Purity expresses which share of the contents is actually the target compound. If it says 98 percent, the rest consists of related chains, residues from the production process and moisture.

How it is measured

In practice that is done with HPLC. The compound is pushed through a column in which components separate by speed. What comes out the other end is shown as a series of peaks. The area of the main peak divided by the total area gives the percentage.

That means something important: the percentage says how much of the detected material is the target compound. Components the detector does not see do not count. An analysis that only shows HPLC is therefore incomplete.

Why identity belongs alongside it

HPLC shows how pure something is, not what it is. For that you need mass spectrometry, which measures the molecular mass and compares it with the expected value. Only with both measurements do you know the compound is right and pure.

Why per batch

Every production batch goes through the same process with small differences in temperature, time and purification. Those differences show in the result. A certificate for a batch from March says little about a batch from September.

That is why we tie every report to the batch number on your label, and not to the product name.

What to look for on a certificate

• Is the batch number on it, and does it match your label.
• Is the test date on it, and is it before the production date of your batch.
• Is there a mass spectrometry analysis in addition to HPLC.
• Is the name of the laboratory on it, and is it an external party.
• Is it also tested for heavy metals.