It is named for 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.

[5][6] When a solution of nitrate ions is mixed with aqueous sodium hydroxide, adding Devarda's alloy and heating the mixture gently, liberates ammonia gas.

Devarda's alloy is a reducing agent that was commonly used in wet analytical chemistry to produce so-called nascent hydrogen under alkaline conditions in situ.

Acid conditions in the Marsh test promote the fast escape of the arsine gas (AsH3), while in hyperalkaline solution, the degassing of the reduced ammonia (NH3) is greatly facilitated.

It was assumed by the supporters of this theory that, before two hydrogen atoms can recombine into a more stable H2 molecule, the labile H· free radicals are more reactive than molecular H2, a relatively weak reductant in the absence of a metal catalyst.