The objective of this study was to elucidate the transport characteristics of amino acids by describing rejection behavior, and charge and partitioning effects of amino acids under different pH and ionic strength conditions. Many studies have taken the importance of pH, charge, and concentration into account and reported the rejection of amino acids by nanofiltration membranes. However, the transport characteristics of amino acids have not been a primary focus due to their complex behavior as a function of pH. Transport equations, membranes and solutes, and filtration methods, and instrumental analysis are all discussed. Includes 20 references, tables, figure.