Analysis of Foods Using Nexera™ Post-Column Amino Acid Analysis System

Introduction

Amino acids are essential nutrients that make up the proteins which form the human body. Analysis of amino acids has a long history of applying firstly to research purposes such as structural analysis and diagnoses of diseases and then to quality control of food products and drugs and other fields. Responding to increasing requests for higher speed analysis in recent years, Shimadzu Corporation developed an online pre-column method* that enables more rapid analysis. On the other hand, the post-column method is still frequently used today because of its wide range of applicability, even though it is a time-consuming technique. Shimadzu post-column method employs an automatic analysis system that utilizes fluorescence derivatization by o-phthalaldehyde (OPA) in detection after separation of the amino acids by gradient elution using a cation exchange column. OPA derivatized amino acids have excellent sensitivity and linearity, and highly sensitive detection of proline and other secondary amino acids is also possible. Because the derivatizatoin is carried out after separation, reaction efficiency is less prone to sample matrix effects. Therefore, this post-column method can detect amino acids with high sensitivity and high selectivity. As separation techniques, two modes are available, the Na type for analysis of proteinogenic amino acids and the Li type for analysis of free amino acids. Although simultaneous analysis of amino acids is conducted using the optimum time programs for these respective separation modes, highly accurate amino acid analysis is possible without labor-intensive preparation using a dedicated amino acid mobile phase kit and reaction reagent kit. This article introduces amino acid analyses of various food products using the Nexera post-column amino acid analysis system, which was recently introduced in the market. *:Please refer to Application News No.L529B.

October 27, 2020 GMT