In order to investigate polysaccharides extracted from both phases of the ATPS, their Fourier-transform infrared (FT-IR) spectrums were recorded from 4000 to 500 cm−1 using films prepared by the dried polysaccharides and KBr pellets. As IR spectrums shown in Fig. 4, the polysaccharide extracted from the bottom phase showed characteristic absorption peaks at 3421.2 cm−1and 2953.9 cm−1from O H and C H, CH2 stretching, and1101.3 cm−1from C O stretching.