"tbe buffer"

The NED method is widely used in the quantitative analysis of nitrite and nitrate in water samples. NED readily undergoes a diazonium coupling reaction in the presence of nitrite to give a strongly colored pink azo compound. The intensity of the color is directly proportional to the concentration of nitrite in the sample. Due to the significant intensity of the developed color even at very low nitrite/nitrate concentrations, lower detection limits and measurement ranges are possible vs. chromotropic acid kits. In addition, the nitrate measurement uses only zinc which is less toxic than cadmium, making handling and disposal safer.