High performance liquid chromatography, known as HPLC, works by using high-pressure pumps to effectively force a sample mixture containing the solvent through a column that contains a solid absorbent material.
This absorbent material interacts differently with each component in the solvent. As the solvent components flow out of the column, they flow at a unique rate.
The difference in flow rate lets each component be separated from the mixture. A detector then determines the identity and concentration of the compounds.