Development of analytical method for determination 8 amino acids and its validation for veterinary use by liquid chromatography-tandem mass spectrometry

The objective of this study was to develop a simultaneous method for 8 amino acids including alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan in veterinary products using LC-MS/MS. To optimize MS analytical condition of 8 amino acids, each parameter was established by multiple reaction monitoring in positive mode. The chromatogram separation was achieved on a C18 column with mobile phase of 0.1% formic acid in D.W. and 0.1% formic acid in acetonitrile for green technology at a flow rate of 0.4mL/min for 5 min with gradient elution. The developed method was validated for mass accuracy, precision, linearity in veterinary products. Calibration curves were linear over the calibration ranges (0.5 - 10 mg/L) for all the analytes r2>0.99. Average recoveries were 92.96 - 105.61% and relative standard deviations (RSD) were 0.27 - 3.5%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 - 0.83 mg/L and 0.12 - 2.52 mg/L, respectively. All values were corresponded with the criteria ranges requested by CD 2002/657/EC. The application of this method will be helpful in quality control analysis of amino acids in veterinary products.