[HPLC Case Study] Automatic Derivatization of Amino Acids and Quantification of D-Amino Acids

High-precision and high-sensitivity analysis of D/L amino acids using online derivatization with an autosampler.

This application note introduces amino acid analysis utilizing the automatic derivatization feature of the Thermo Scientific Vanquish Flex UHPLC system. Online chiral derivatization using OPA/NAC was employed to conduct quantitative analysis of D-aspartic acid (D-Asp), D-glutamic acid (D-Glu), and D-serine (D-Ser). By automating the process from derivatization to injection within the auto-sampler, we streamline complex sample preparation while achieving high reproducibility and quantitativeness. Furthermore, we demonstrate the quantification of D-amino acids present in fermented foods such as apple cider vinegar, grain vinegar, and whey, showing that sensitive and selective analysis is possible even in complex sample matrices. **Features** - Separation of D and L forms of eight amino acids including D-Asp, D-Glu, and D-Ser in under 15 minutes. - High reproducibility confirmed with retention time RSD ≦ 0.16% and area value RSD ≦ 0.22%. - Good linearity in the calibration range of 1–500 ng/mL (R² ≧ 0.9999). - Examples of D-amino acid quantification in fermented foods (apple cider vinegar, grain vinegar, whey) along with chromatograms are presented.

Analytical Equipment and Devices