Amino Acid Analysis System

For high-sensitivity measurement of amino acids in foods and biological samples

The analysis of amino acids plays an important role not only in the food industry, but also in natural product and pharmaceutical fields. This system uses detection by post-column fluorescence derivatization, with o-phthalaldehyde (OPA) / N-acetylcysteine as the reaction reagent, to selectively and with high sensitivity quantitate the amino acids contained in samples with high levels of contaminants.


  1. Selectively detects amino acids based on Shimadzu's highly acclaimed post-column reaction technology and high-sensitivity fluorescence detector.
    Detects amino acids with over ten times higher sensitivity than the ninhydrin method (UV detection), by using a derivatization method that provides selective reaction with amino radicals, together with fluorescence detection.
  2. Outstanding Reproducibility
    Because derivatization occurs after separation in the column, reactions are not affected by the sample matrix. Therefore, analyses can be performed with good precision.
  3. Easy to Operate
    Since column eluant is automatically derivatized by mixing it with the reaction reagent, it saves time and tedious tasks.
  4. The mobile phase and reaction solution are available as a kit, which means solutions can be prepared with minimal fuss.

Detection Principle

After amino acids are separated by cation exchange chromatography, aqueous sodium hypochlorite solution (to convert prolines, and so on, to primary amines) and OPA/N-acetylcysteine reagent are added consecutively to the column eluant, then the resulting fluorescent derivatives are detected.

Analysis Example

Two models are available - an "Na" model, capable of rapidly analyzing amino acids hydrolyzed from protein, and an "Li" model, capable of separating naturally-occurring free amino acids. The figure below and to the left is a chromatogram of a standard solution of hydrolyzed protein amino acids containing 17 components, measured using the "Na" model. The figure below and to the right shows results from analyzing soy sauce diluted by 200 times with a pH 2.2 lithium citrate buffer solution (for sample dilution) and filtered through a membrane filter.
Reference: Amino Acid Analysis
GC/MS Metabolite Mass Spectral Database(amino acids, fatty acids, and organic acids)

For Research Use Only. Not for use in diagnostic procedures.