1987 Volume 36 Issue 5 Pages 316-319
The usefulness and a new concept of the cyclic FIA were demonstrated through the determination of free cyanide (CN-) by using didodecyldimethylammonium bromide(DDAB)/uranine/sodium hydroxide chemiluminescence system. The CN- sample dissolved in sodium hydroxide solution was injected into a circulating stream of reagent solution containing Al2(SO4)3 as a neutralizer of sodium hydroxide. Under recommended conditions for cyclic FIA, i.e., 1×10-4M uranine, 5×10-4M DDAB and 5×10-5 M Al2(SO4)3 and 20 μl injection of CN-sample dissolved in 5×10-3 M sodium hydroxide, 120 samples were analyzable with a detection limit of 0.5 pg. The sample analyzing capacity of the present system was 2 times larger than that of the conventional FIA system. The strongest enhancer after CN-, S2- did not interfere the signal for CN- after 120 sample injections. The present cyclic FIA system for CN- determination could be operated for at least 30 days.
