Improved method for the measurement of large neutral amino acids in biological matrices

A high-performance liquid chromatographic method for measuring neutral amin o acids in rat sera, brain tissues, and perfusates was developed by using o micron -phthalaldehyde sulfite as a pre-column derivatization reagent. With the present method, it was possible to separate the neutral amino acids wi thin a single run in 25 min, while the acidic amino acids were eluted near or at the solvent front. The recovery was above 88.8% with a relative stand ard deviation (RSD) below 4.2%. The within- and between-day assay reproduci bility for the determination of rat serum amino acids showed RSDs below 1.3 5 and 7.61%, respectively. In the present study, the neutral amino acids we re assayed with high sensitivity, accuracy and good reproducibility in a re latively short time and on a small sample size. (C) 2001 Elsevier Science B .V. All rights reserved.