Continuous on-line derivatization and selective separation of D-aspartic acid by a capillary electrophoresis system with a continuous sample introduction interface

✍ Scribed by Liuyin Fan; Yuqiao Cheng; Hongli Chen; Lihong Liu; Xingguo Chen; Zhide Hu

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 95 KB
• Volume: 25
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200305881

✦ Synopsis

Abstract

A rapid and selective method is described for the separation of D‐aspartic acid (D‐Asp) using a continuous on‐line derivatization system coupled to capillary electrophoresis (CE). D‐Asp was derivatized using o‐phthaldialdehyde/N‐acetyl‐L‐cysteine (OPA/NAC). By on‐line derivatization, amino acid enantiomers were automatically and reproducibly converted to the UV‐absorbing diastereomer derivatives which were separated by capillary zone electrophoresis (CZE) in the presence of 10 mmol/L β‐cyclodextrin (__β‐__CD). Under the investigated separation conditions, D‐Asp is resolved from L‐aspartic acid (L‐Asp) and other amino acids in a standard mixture of amino acids. The separation could be achieved within 4 min and the sample throughput rate can reach up to 16 h^‐1^. The repeatability (defined as relative standard deviation, RSD) was 3.21%, 3.58% with peak area evaluation and 3.72%, 4.03% with peak height evaluation for L‐Asp and D‐Asp.