Abstract: Inhibitory function of luminol-Co(II)-H2O2 chemiluminescence by Cd(II) was studied in this research using static- state-injection chemiluminescence, and it was applied to determine Cd(II) in water. The results indicated that Co(II) enhanced the chemiluminescence intensity of luminol-H2O2 , while Cd(II) restrained the chemiluminescence intensity of luminol-Co(II)- H2O2. Further research indicated that the restraint of luminol-Co(Ⅱ)-H2O2 chemiluminescence by Cd(II) had a relationship with the concentration of Cd(II) in water. The linear range is 1.0 × 10-7～5.0 × 10-6 g/ml. The limit of detection is 3.2 × 10-8 g/ml. The method was applied to the determination of Cd(II) in water and satisfactory result was obtained. Meanwhile, the possible reaction mechanism was put forward based on the further study.

Key words: chemiluminescence, cadmium, inhibitory function, reaction mechanism