HPLC - separation technique; which involves small volume of the liquid sample injection into the stationary phase, in that phase individual components of the sample moved with a liquid mobile phase forced by high pressure. In HPLC, the components are separated from one by one. The column packing interacts between their molecules by various chemical and/or physical interactions with the packing particles. At the exit of this tube column these separated components are detected by the device flow through detector measures their amount. The output from the detector is called a chromatogram.
For the identification of individual compounds in the sample
The compounds are identified based on its retention time (time taken for compound to elute from the column after injection) and depending on the detector used.
To measure the amount of a compound in a sample
In order to make a quantitative analysis of a compound in the sample, known amount/concentration of the interested compound is injected, then its peak height / area is measured. In many of the cases, it is having a linear relationship between the Area or Hight and the amount of sample.
This technique mostly used to determine the trace amount of compounds. It is Used in Various fields such as pharmaceutical, biological, toxicology, and environmental studies etc.,.