owadays solubility of amino acids is highly important in determining biological action of bio-macromolecules
such as proteins. In the present study the solubilities of three amino acids namely L-cystine, L-tyrosine andL-leucine in aqueous NaCl solution at various pHs were estimated by gravimetric method at 298.15 K. The exper-imental results showed a salting-out effect for L-tyrosine andL-leucine while a salting-in effect was observed
for L-cystine in different experimental conditions. In this study an attempt was made to explore the probable
m ode of int era ct ion of a mino ac i ds wi th aq ueou s Na Cl so lut ion s at var ious pHs acti ng beh ind th e sa lti ng -in
and salting-out effects. This will definitely enrich the knowledge on the actual solubility results of amino acids.