The classic method for the determination of nitrite in food is based upon its ability to convert aromatic amines into diazonium ions, which, in turn, are coupled to another aromatic compound in order to produce an azo dye (the Griess-Romijn reaction) [6]. This is the base of many spectrophotometric methods. The most common arrangement utilizes sulphanilamide and N-(1-naphthyl)ethylenediamine as the target amine and coupler, respectively, with the product of the reaction detected at 540 nm. Nitrate is normally chemically reduced to nitrite and determined by the same type of reaction. A variety of reducing agents have been investigated to facilitate this conversion and include amalgamated cadmium [7], copperized cadmium [8] and zinc [9], and more recently, photo-induced reduction [10]. Other current methods for the determination of nitrite and nitrate rely on segmented-flow or flow-injection analysis variants of the traditional colorimetric Griess diazotisation procedure [11], [12], [13] and [14].