Rapid determination of glutamine in biological samples by high-performance liquid chromatography.

A high-performance liquid chromatographic method for the determination of glutamine in biological samples is presented. Glutamine was derivatized with ortho-phthalaldehyde reagent containing 3-mercaptopropionic acid and separated by reversed phase chromatography on a C18 column containing 3-microns particles. No interference from other amino acids was observed. The assay was linear over a range from 1 to 2,000 mumol/l. Analytical recovery of plasma samples spiked with glutamine was 98.6 +/- 3.8%. Within- and between-batch imprecision were 1.5% and 2.2%, respectively. The derivatization step was fully automated. Total analysis time, including derivatization and chromatography, amounted to 6 min. The method can be used for the determination of glutamine in plasma, urine, cerebrospinal fluid and tissue homogenates.