Simultaneous Identification and Quantification of Amino Acids in Biofluids by Using Reactive 19F-Tag

Quantification of each individual amino acid in a biofluid is of great importance in biological and chemical analysis. We herein developed an efficient and simple method of 1D 19F NMR to identify and quantify the amino acids close to the phys-iological conditions. This method relies on effective reaction between the 19F-tag and amino acids in aqueous solution to generate stable amide products that have distinguishable 19F chemical shifts. Each 19F-derivatized amino acid has its own characteristic chemical shifts and can be readily identified at a concentration of as low as 1 µM by direct 1D NMR. The characteristic 19F-chemical shifts together with the additional fingerprint profile of the amino acid derivatives permit straight-forward and simultaneous identification and quantification of the individual amino acids in aqueous solution. The high per-formance of this method has been demonstrated in biofluids, fetal bovine serum (FBS) and cell lysates, and the established method shows great potentials in metabolomics and biochemical analysis.