FLOW-INJECTION CHEMILUMINESCENT DETECTION OF TRACE CO(II) WITH DIBROMOALIZARIN VIOLET-H2O2-CTMAB SYSTEM

Chemiluminescence was observed when dibromoalizarin violet was oxidize d with hydrogen peroxide in alkaline solution. Trace amounts of Co(II) catalysed this CL reaction strongly, especially in the presence of th e cationic surfactant cetyltrimethylammonium bromide, and the CL inten sity was proportional to the concentration of Co(II). A flow injection system with CL detection was established to investigate this CL syste m. The optimum conditions for this CL reaction were investigated in de tail, and the optimized flow injection parameters were determined by t he modified simplex method. A CL analytical method for determination o f ultratrace amounts of Co(II) was developed with a detection limit of 4 pg/mL. It was used for analysis of natural water samples, and the r esults compare very well with those from GFAAS. A possible mechanism f or this CL reaction is proposed on the basis of studying CL spectra, a bsorption spectra, fluorescent spectra and HMO treatment for the reage nt molecule. The effects of various types of surfactants on CL reactio n are also discussed.