Flow-injection chemiluminescence determination of hydrazine using on-line electrogenerated BrO- as the oxidant

A novel chemiluminescence flow system for the determination of hydrazine is presented. It is based on the enhancement effect of hydrazine on the chemi luminescence reaction between luminol and BrO- in alkaline media. The oxida nt BrO- was on-line electrogenerated by constant current electrolysis, resu lting in the elimination of the inconvenience of its instability. The varia bles that affect the reaction were investigated and optimum condition was e stablished. Hydrazine can be determined in the range of 0.01-10 mug ml(-1) with a detection limit of 0.003 mug ml(-1) (3 sigma). A complete analysis c ould be done in 1 min with the relative standard deviation of 3.7%. The pro posed method is suitable for the automatic and continuous on-line monitorin g of low level of hydrazine. A few examples of the determination of hydrazi ne in drinking and river waters are given.