Continuous on-line derivatization and determination of amino acids by a microfluidic capillary electrophoresis system with a continuous sample introduction interface

摘要

An automatic,rapid and continuous on-line derivatization system coupled to microfluidic capillary electrophoresis (CE)for the determination of amino acids using o-phthalidialdehyde/N-acetyl-L-cysteine (OPA/NAC)as teh derivative agents has been developed.By on-line derivatizatin,amino acids were automatically adn reproducibly converted to the UV-absorbing derivatives,which were separated by capillary none electrophoresis (CZE).Optimization of derivatization and separation condition was carried out to achieve both good sensitivity and separation efficiency.The separation could be achieved within 4 min and sample throughput rate can reach up to 16h~-1.The repeatability(defined as relative standard deviation,R.S.D.)was 2.56,2.85,3.24 and 3.60%with peak area evaluation and 2.93,3.12,4.20 and 4.91%with peak height evaluation for arginine (Arg),phenylalanine (Phe),serine (Ser)and glycine (Gly),respectively.The limits of detectin (S/N=3)were 10.46,13.14,34.39 and 44.79 mumol/l for Arg,Phe,Ser and Gly,respectively.Major advantages of th proposed method include improved precision and efficient automation of the derivatization by the FI system and the enhanced sampling frequencies by the combined Fi-CE system.