Considerations for amino acid analysis by liquid chromatography-tandem mass spectrometry: A tutorial review

Amino acids are present in a variety of matrices from biological fluids to plant and animal tissues. We discuss options for amino acid extraction, sample clean-up and protein hydrolysis. Chromatographic separation of native amino acids is difficult due to their structure and physiochemical properties. Most analysts derivatise amino acids prior to analysis which improves the signal-to-noise ratio, provides more efficient ionisation and allows the use of reverse phase chromatography. Since chiral analysis is becoming increasingly important, we discuss chiral column chromatography and the use of chiral derivatisation agents. The choice of detector and parameters is based on a wide array of criteria including whether amino acids are native or derivatised and if targeted or untargeted analysis is being performed. This tutorial review aims to act as both a guide and to provide an overview of the techniques scientists currently employ for the analysis of amino acids via liquid chromatography-tandem mass spectrometry. (C) 2020 Elsevier B.V. All rights reserved.