The Difference Between 99 Percent and 99.9 Percent Is Not 0.9 Percent
Subtracting 99.0 from 99.9 gives an answer that is arithmetically correct and analytically useless. The remainder shrinks tenfold, and what it contains decides whether the two materials are comparable at all.
What Purity Actually Means: Impurities, Certificates and Specifications
A purity percentage is a statement about one chromatogram, one detector and one day, not about the contents of the bottle. This hub maps impurity thresholds, response factors, specifications and reference materials.