Rapid and Environment-Friendly LC-MS/MS for Simultaneous Analysis of Amino Acids in Veterinary Medicine.

Background: Amino acid supplements are crucial for animal health and productivity. Traditional analysis methods face limitations like complexity, long testing times and toxic reagents. Therefore, a more efficient and reliable method is needed.

Objectives: This study aimed to develop and validate an efficient method for the simultaneous analysis of eight amino acids commonly used in veterinary medicine: alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan.

Methods: We analysed eight veterinary amino acid preparations. From 100 registered products, we selected 35. After confirming ingredients, we diluted them to 1 mg/L with 50% acetonitrile (ACN) and filtered them using a 0.2 µm RC filter for liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis.

Results: All analytes showed excellent linearity (r > 0.99) within 0-10 mg/L. The limits of detection (LOD) ranged from 0.04 to 0.83 mg/L, and the limits of quantification (LOQ) ranged from 0.12 to 2.52 mg/L. Average recovery ranged from 92.96% to 105.61%, with relative standard deviations (RSD) from 0.27% to 3.50%, meeting CD 2002/657/EC standards. Six out of the 35 products (17.14%) did not meet regulations.

Conclusions: The method developed in this study offers an efficient and reliable approach for the simultaneous analysis of essential amino acids in veterinary medicine. Implementing this method can improve the quality control of amino acid products, enhancing animal health and productivity. This study also highlights the need for stringent domestic management and continuous monitoring. By overcoming traditional technique limitations, this validated method ensures the quality and efficacy of amino acid supplements in the veterinary industry.