Analysis of natural carbohydrate biopolymer-high molecular chitosan and carboxymethyl chitosan by capillary zone electrophoresis

Chitosan and its derivatives have been widely used in many fields for their various function, there were some difference in bioactivities and applications between them. In this paper, a direct capillary zone electrophoresis (CZE) method without any pre-treatment was developed for separation of chitosan and its derivative, a water soluble chitosan called carboxymethyl chitosan (CM-chitosan), which was proved to be rapid and effective with satisfactory resolution. Optimization of conditions including pH, concentration of the buffer, and length of column were investigated, showing that when employing 50 mM sodium phosphate at pH 2.0 and untreated fused silica capillary, high-molecular weight chitosan and CM-chitosan were baseline separated with ultraviolet (UV) detector with satisfactory repeatability and excellent linear responses. Therefore, this method could be applied to separate and identify chitosan and CM-chitosan in biological samples and commercial products.