Marsh-Gutzeit test

The Marsh-Gutzeit Test Arsenic, from all of its soluble compounds, is reduced (by nascent hydrogen ) in acidic solution to arsane, ASH3, a colorless gas smelling like garlic ... 

The Gutzeit Test.3—This test is as accurate as the Marsh test and the apparatus necessary is comparatively simple. It consists in allowing the arsine to react with strips or discs of dry filter paper impregnated with silver nitrate or, in the more recent modifications of the method, mercuric chloride or bromide. 

Estimation Gravimetrically as Sulphide as Magnesium Pyroarsenate—Volu-metrically by Iodometric Methods with Potassium Bromate, etc.—The Marsh Test—The Gutzeit Test—Fleitmann s Test—Colorimetric Methods— Microohemioal Methods—Determination of Arsenic in Gases. 

Note Small amounts of As(lll) or As(V) can be identified by the response to the Marsh, Gutzeit, or Fleitmann tests (see references at the beginning of this section)... 

Determinations of very small amoxmts of arsenic, such as 0.1 mg or less, were traditionally done with the Marsh test or the Gutzeit test invented in the late nineteenth century. Method (a) of the European Pharmacopoeia can be considered a modified Gutzeit test, but whereas this originally used silver nitrate or mercury(II)chloride to detect any arsenic present, method (a) uses mercury(II)bromide. 

---