Sensitive determination of nanogram levels of diacerein in a pharmaceutical formulation by flow injection chemiluminescence analysis

A simple, sensitive and inexpensive flow injection chemiluminescence (FI-CL) method for the determination of diacerein was proposed. It was based on the greatly enhancive effect of diacerein on the CL reaction between luminol and hydrogen peroxide,in alkaline medium. The enhanced CL intensity was linear with the concentration of diacerein over the range 1.0-500 ng/mL with a detection limit (3 sigma) of 0.2 ng/mL. The relative standard deviation was 1.1% (n = 8, 20 ng/mL diacerein) and the sample throughput was about 120 samples h(-1). This simple method has been successfully applied for the determination of diacerein in a pharmaceutical formulation without interference from its potential impurities. The degradation of diacerein was also investigated briefly.