Charge density quantification of polyelectrolyte polysaccharides by conductometric titration : an analytical chemistry experiment

An easy analytical method for determination of the charge density of polyelectrolytes, including polysaccharides and other biopolymers, is presented. The basic principles of conductometric titration, which is used in the pulp and paper industry as well as in colloid and interface science, were adapted to quantify the charge densities of a negatively charged polysaccharide (pectin) and a positively charged biopolymer (chitosan), two biomacromolecules commonly used in food and biomaterials applications. This novel conductometric titration method can be easily applied in most analytical chemistry teaching laboratories, due to its ease-of-use, safety, and educational benefits. This analytical technique can also be used in a wide-range of laboratory activities and has extensive research applications in areas of chemistry involving charged biopolymers, such as food science, materials science, and physical chemistry