This standard specifies a method of measuring the concentration of nitrate and nitrite nitrogen in water and in wastewater.The method is conveniently applied after the determination of free and saline ammonia, using SANS 5217, since the residue in the distillation flask after the performance of SANS 5217 can be used as the test portion to be reduced with Devarda's alloy.Nitrite nitrogen should be determined separately by using SANS 6777 if the concentrations of both nitrate and nitrite nitrogen are required.