[en] The phase separation time (PST) of TBP/n-dodecane system against water was studied using an indigenously developed light scattering technique. The phase separation time was measured as a function of concentration of TBP in n-dodecane ranging from 5 vol % to 40 vol %. An attempt was made to correlate PST values with the interfacial surface tension (IST) values of the same system. The IST values were obtained using the drop weight technique by applying Smith's correction factor to the Tate's law. It was observed that with the increase in concentration of TBP in organic phase, the phase separation time increases while the IST value decreases. This can be attributed to the increase in the hydrophilicity of the organic phase with increasing TBP concentration. (author)