What Is HPLC Testing?

High-performance liquid chromatography separates the components of a sample by pushing it through a packed column under pressure. Different molecules travel at different speeds and emerge at different times.

The resulting chromatogram shows peaks. The area of the main peak relative to total peak area gives a purity percentage.

What it cannot tell you

HPLC measures how much of the sample is one dominant component. It does not confirm that the component is the molecule claimed. That requires mass spectrometry.

A purity figure without an identity test is an incomplete answer, however high the number.