We report on a simple and sensitive chemiluminescence (CL) method to determine nitrazepam. This method is based on the fact that rhodamine 6G (Rh6G) enhanced the weak CL emission of the reaction of hexacyanoferrate with nitrazepam, and that it was further enhanced by silver nanoparticles (AgNPs). The effects of the concentrations of K3Fe(CN)6, Rh6G, AgNPs and NaOH on the CL reaction were investigated. Under the optimum conditions, the CL intensity was proportional to the concentration of nitrazepam in the range from 1.0 nM to 10.0 μM. The detection limit (3σ) was at 0.1 nM. The relative standard deviation was 2.1% (at a 0.1 μM concentration and for n = 11). The method was successfully applied to the determination of nitrazepam in Coca-Cola beverage, urine and plasma, and the recovery was 98 -103%. We also considered the possible CL reaction mechanism.

A post-chemiluminescence (PCL) phenomenon was observed when palmatine was injected in a mixture of N-bromosuccinimide (NBS) and alkaline dichlorofluorescein (DCF) after the chemiluminescence (CL) reaction of NBS-alkaline DCF had finished. Based on the PCL reaction, a rapid and sensitive method for the determination of palmatine was established. Under optimum conditions, the CL intensity was linear, with the concentration of palmatine in the range of 5.0 × 10(-9) to 1.0 × 10(-6) M. The detection limit was 6.0 × 10(-10) M for palmatine. The relative standard deviation for 11 parallel measurements of 1.0 × 10(-7) M palmatine was 1.5%. This method was applied to the determination of palmatine in pharmaceutical samples and biological fluids, with satisfactory results. The possible reaction mechanism is discussed briefly.

A chemiluminescence (CL) phenomenon was observed when gossypol was injected into a reaction mixture of N-bromosuccinimide (NBS) and alkaline dichlorofluorescein (DCF). Based on this phenomenon, a rapid and sensitive method for the determination of gossypol was established. Under the optimum conditions, the linear range was from1.0 × 10 -9 to 1.0 × 10 -6 M. The detection limit was 1.0 × 10 -10 M. The method has been applied to the determination of gossypol in cottonseed, cottonseed oil, pharmaceutical and biological fluids with satisfactory results. The possible CL reaction mechanism was discussed briefly.