N-(1-Naphthyl)ethylenediamine dihydrochloride

N-(1-Naphthyl)ethylenediamine 2HCl is a diazonium salt that is used as an analytical reagent for the determination of nitrite ion in biological samples. It can be prepared by reacting 1-naphthylamine with ethylenediamine and hydrochloric acid. The optimum concentration of N-(1-naphthyl)ethylenediamine 2HCl is between 0.5 and 1.0 M, which should be determined before use. Sulphuric acid or sodium hydroxide can be added to adjust the pH of the solution to around 2.5, although this may change the color of the solution from orange to yellow. The reaction product is then extracted into chloroform and dried over anhydrous sodium sulphate or magnesium sulfate, followed by filtration and evaporation under reduced pressure at 40°C until dryness. The final product is stored in a dark place away from