2009 Volume 58 Issue 8 Pages 723-729
The reduction of nitrate to nitrite is needed for a colorimetric determination of nitrate with the Griess reaction. The reduction rate of nitrate to nitrite by connecting some copper-cadmium reduction columns in a continuous-flow analysis was investigated. The reduction rate of nitrate did not depend on the concentrations of nitrate and nitrite. It was confirmed that a reduction rate of 95% or more was usually realized using a single column. Plural reduction columns were connected and the obtained reduction rate was evaluated. Consequently, the connection of the columns increased the reduction rate and a steady value of the reduction rate (99.9% or more) was achieved by three connected columns.
