Various methods for the individual as well as simultaneous estimation of amino acids using various techniques like HPLC and other way outs like electrophoresis have been described in this review paper. The amino acid determination by using HPLC can either be done by using pre-column or post column derivatization. The amino acid is first derivatized into a particular derivative and then is analysed into the column in the case of pre-column derivatization, whereas in the case of post column derivatization, the amino acid is first passed through the column for the sake of separation and then the separated amino acids are derivatized into their such derivatives which can be detected by fluorescence detector. Out of the above two mentioned techniques, pre-column derivatization is used more oftenly than the post column derivatization. Few of the most commonly used derivatization agents are phenylisothiocyanate, o-phthalaldehyde+2-mercaptoethanol, dansyl chloride, phenylthiohydantoin etc
