Bettendorff’s test

The reduction of arsenious acid by means of stannous chloride has already been described (p. 28), the well-known Bettendorff s test depending upon the reaction.2 In the presence of concentrated hydrochloric acid, a voluminous brown precipitate, consisting mainly of yellow arsenic with small amounts of tin, is formed. Velocity measurements lead to the view 3 that the reaction takes place between arsenious and chloride ions and the complex H3SnCl4. Dilution with water decreases the velocity and ultimately prevents precipitation. The reaction is endothermic.4... 

Applied as a microchemical test, Bettendorff s test is ten times as sensitive as the Marsh test.8... 

Tin(II) chloride solution and concentrated hydrochloric acid (Bettendorff s Test) A few drops of the arsenite solution are added to 2 ml concentrated hydrochloric acid and 0-5 ml saturated tin(II) chloride solution, and the solution gently warmed the solution becomes dark brown and finally black, due to the separation of elementary arsenic. 

Arsenite. (i) Action of H2S upon acid solution (III. 12, 1). (ii) Silver nitrate solution test (III. 12, 2), and absence of precipitate with magnesium nitrate reagent (III.12, 3) or on boiling with ammonium molybdate solution and nitric acid, (iii) Bettendorff s test (III.12, 6). 

Aqueous [SnCls]" in hot, concentrated HCl reduces As (As slowly) to the flocculent, dark brown element in Bettendorff s test ... 

Detection Dry Tests, Wet Tests, Bettendorffs Test, Thiele s or Bougault s Test, The Reinsch Test. 

Hi) Fleitmann s or Bettendorffs tests Negative results are obtained when these are applied to antimony compounds (distinction from arsenic). 

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