Targeted Quantification of Amino Acids by Dansylation.

Quantification of amino acids in biological samples is a critical tool for studying metabolism. Although many methods for amino acid analysis exist, important considerations include ease of sample preparation, dynamic range, reproducibility, instrument availability, and throughput. Here, we present a simple, rapid, and robust method for the analysis of amino acids by chemical derivatization and liquid chromatography-mass spectrometry (LC-MS). We provide a detailed protocol for the analysis of 20 proteinogenic amino acids in biological samples which will enable straightforward implementation on modern LC-MS instruments.