Lab and analysis
HPLC
Definition
High performance liquid chromatography, the most common method for assay and impurity testing of organic chemicals and APIs.
In HPLC a liquid sample is pumped through a packed column and its components separate by how they interact with the column. A detector, often UV, records each peak. Peak areas give the assay and the level of each impurity.
Purity by HPLC area percent assumes all components respond equally to the detector, which is not always true. Assay against a reference standard is more accurate.
Related terms
- Gas chromatography (GC)A separation method for volatile compounds, used for solvents, residual solvents and many organic intermediates.
- Impurity profile (related substances)The identity and amount of impurities in a material, often measured by HPLC as related substances.
- HPLC gradeSolvent of very high purity with low UV absorbance and low residue, made for high performance liquid chromatography.