|
}} Devarda's alloy (CAS # 8049-11-4), is an alloy of aluminium (44% – 46%), copper (49% – 51%) and zinc (4% – 6%). Devarda's alloy is used as reducing agent in analytical chemistry for the determination of nitrates after their reduction to ammonia under alkaline conditions. It owes its name to the Italian chemist Arturo Devarda (1859–1944), who synthesised it at the end of the 19th century to develop a new method to analyze nitrate in Chile saltpeter. It was often used in the quantitative or qualitative analysis of nitrates in agriculture and soil science before the development of ion chromatography, the predominant analysis method largely adopted worldwide today. ==General mechanism== When a solution of nitrate ions is mixed with aqueous sodium hydroxide, adding Devarda's alloy and heating the mixture gently, liberates ammonia gas. After conversion under the form of ammonia, the total nitrogen is then determined by Kjeldahl method. The reduction of nitrate by the Devarda's alloy is given by the following equation: :3 + 8 Al + 5 + 18 → 3 + 8 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Devarda's alloy」の詳細全文を読む スポンサード リンク
|