Establishment of highly sensitive analytical method for chondroitin sulfate by flow injection chemiluminescence

A simple and sensitive flow injection chemiluminescence (FI-CL) method has been developed for the determination of chondroitin sulfate (CS). The method is based on the sensitization effect of enzymatic products of CS on the luminol-H 2 O 2 system. Experimental parameters affecting FI-CL method such as concentrations of luminol, H 2 O 2 and NaOH and the standing time of luminol alkaline solution were optimized. Under optimum conditions, the calibration plot between CS concentration and the change of CL intensity was linear in the range of 25 ng/mL∼250 ng/mL. The limit of detection (LOD) was 5 ng/mL and the average relative standard deviation (RSD) of CL intensity was 2.5%. The method was successfully applied to the quantitative analysis of CS concentration in drugs. Compared with the reported methods so far, the established method is simple, sensitive, accurate and rapid.