What the percentage means
A purity percentage expresses the proportion of a sample attributed to the intended material, as measured by a specific analytical method such as HPLC. Because it is method-dependent, the figure is reported together with the method that produced it.
Reading it in context
A purity figure should be read alongside an identity confirmation (often from mass spectrometry). Purity says how much of the sample is the main component; identity says whether that component is the intended molecule. The two together are more informative than either alone.
Honest reporting
Purity figures belong to specific batches and specific methods. A responsible supplier reports the figure supplied for a batch rather than a general claim, and does not guarantee a purity result.
Frequently asked questions
Is a higher percentage always the whole story?
No. Purity should be read with an identity confirmation and the method used.
Why isn’t purity quoted as a general figure?
Because it is batch- and method-specific; it is reported per batch, not as a blanket claim.