The high selectivity and high sensitivity measurement of amino acids requires the derivatization as amino acids do not absorb in UV-Vis region or fluorescence. Pre-column and post-column derivatization methods can be used for the analysis of amino acids. In the case of pre-column derivatization, the sample is derivatized in the autosampler and then separated in a C18 or similar column and detected. On the other hand, in the case of post-column derivatization, the sample is separated using an ion-exchange column or similar first, then mixed with reaction solution for derivatization and then detection. 
 

Jasco offers several analysis systems:

• Pre-column derivatization system using orthophtalaldehyde (OPA) for fluorescence detection
• Pre-column derivatization system using Dabsyl chloride for absorbance detection
• Post-column derivatization system using OPA for fluorescence detection
• Post-column derivatization system using ninhydrin for absorbance detection. 

The pre-column derivatization method has many advantages such as a simple system configuration, wide selectivity of derivatization reagents, and offers a high sensitive measurement.

In this application, 19 amino acids were measured using OPA pre-column derivatization through the automated pre-column derivatization function of autosampler. The RHPLC conditions drastically reduced the measurement time.