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- P-ISSN 1225-0163
- E-ISSN 2288-8985
Multiple-step gradient method was used for the analysis of free amino acids in physiological fluids by high-performance liquid chromatography with diode array detector on the Amino Quant <TEX>$C_{18}$</TEX> column under the condition of pH 7.2 of buffer solutions. Plasma samples of normal Korean people and abnormal Korean people who have schizophrenia were subjected to derivatization with o-phthalaldehyde in the presence of 3-mercaptopropionic acid. Quantitative analysis of amino acids in physiological fluids by internal standard method gave highly reproducible results within a relative standard deviation of less than 2~6%. And amino acids amounts of physiological fluids of Korean people gave some different results from those of foreigners. There was large differences in tyrosine amount between normal and abnormal man.