Structural change in dextran: Mechanism of insolubilization by adsorption on the air-liquid interface

To clarify the insolubilization mechanism of water-soluble dextran, the ass ociation of dextran in water was studied by dynamic light scattering measur ements and a surface chemical approach. Dynamic light scattering measuremen ts indicated that insolubilization of dextran is accompanied by a structura l change in dextran. Surface tension data for dextran molecules revealed a structural change in dextran molecules at the air-liquid interface. These r esults suggest that insolubilization of dextran molecules occurred through an adsorption process at the air-liquid interface. Insolubilization of dext ran molecules can be reduced by inhibition of this structural change in dex tran molecules. The presence of boron as an impurity was found to trigger p recipitation based on inductively coupled plasma mass spectrometry measurem ents and precipitation tests. (C) 1999 Academic Press.