This standard was last reviewed and confirmed in 2019. Therefore this version remains current.
Based on dissolution of a test sample in water, distillation of the ammonia after displacement by an alkali solution. Absorption in an excess of standard volumetric sulphuric acid solution and back-titration with standard volumetric sodium hydroxide solution in the presence of methyl red/methylene blue mixed indicator. A typical distillation apparatus is shown in a figure.
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|std 1 40|
|std 2 40||Paper|
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Stage: 90.93 (Confirmed)
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