Question

How to determine nitrite using cadmium reduction column by titration method ?
I am going to do this experiment in the laboratory & I need to find out the exact measurements for this method.

Answer 1

A filtered sample is passed through a column containing granulated copper-cadmium to reduce nitrate to nitrite. The nitrite (that originally present plus reduced nitrate) is determined by diazotizing with
sulfanilamide and coupling with N-(1-naphthyl)-ethylenediamine dihydrochloride to form a highly colored azo dye which is measured, spectrophotometrically. Separate, rather than combined nitrate-nitrite, values are readily obtained by carrying out the procedure first with, and then without, the Cu-Cd reduction step

See Nitrogen, Nitrate-Nitrite (Spectrophotometric, Cadmium Reduction) at: https://monitoringprotocols.pbworks.com/f/EPA+353_3.pdf