Colorimetric Determination of Poly (ethylene glycol)

Abstract

Poly (ethylene glycol) (PEG) has widely been used as a nonionic surfactant for dispersion, solubilination, and dehydration of protein or lipid. Recently, PEG is used fordfsf purification or concentration of biological substances such as viral suspenlion. Sensitive method is required for the measurement of PEG in the presence of impurities since the biological substances are usually contained large amounts of proteins or lipids. By Stevenson's method which is widely used for the measurement of PEG, it was difficult to measure the PEG in the presence of protein or lipid because nonspecific color development occurred by impurities. In this paper, we determined the substances which caused the nonspecific color development and found the procedure which removed them from samples. We described also more sensitive procedure for the measurement of PEG by the modification of concentration of chemical reagents which are used in Stevenson's method.