The Reflectoquant Nitrate test strips can be used for the rapid determination of the nitrate content in water and also with fruit and vegetables to help decide whether a given delivery batch can be released for use in a specific product (e.g. baby foods). On the strip nitrate ions are reduced to nitrite ions by a reducing agent. In the presence of an acidic buffer, these nitrite ions react with an aromatic amine to form a diazonium salt, which in turn reacts with N-(1naphthyl)-ethylene-diamine to form a red-violet azo dye that is determined reflectometrically on the RQflex. For pre-testing a sample in an economic and quick way to check for nitrite interferences or to estimate the nitrate concentration and a possible dilution factor prior to using this quantitative method we recommend our semi-quantitative MQuant test strips for nitrate and nitrite. Further quantitative determination methods can be found with our Spectroquant tests.