Polyvinylpyrrolidone (Povidone) is a linear aqueous polymer made by N-vinyl-2- pyrolidone, and is divided from K-10 to K-120 by the viscosity characteristics. When Povidone is analyzed by aqueous eluent, the retention time is delayed or the peak area is lessened due to the hydrophobic interaction between Povidone and the packing material. In order to solve the problems above, adding acetonitrile into the eluent is effective. The comparison of the peak shapes by changing the acetonitrile concentration of the eluent from 0 % (only 0.1M NaCl solution) to 50 % shows for the analysis of Povidone. In case of K-30, high reproducibility of the analysis was obtained from 30 % to 45 % concentration, but the retention time was delayed with 50 % acetonitrile because of the hydrophilic interaction between K-30 and the packing materials. It is important to study the suitable concentration of acetonitrile.


Sample : 100 µL
Polyvinylpyrrolidone (K-30) 0.1%

Columns      : Shodex OHpak SB-806M HQ (8.0 mm I.D. x 300 mm) x 2
Eluent       : 0.1 M NaCl aq./CH3CN
Flow rate    : 1.0 mL/min
Detector     : RI
Column temp. : 40 °C