Azotometer

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Azotometer burette: the resulting nitrogen volume is read off the upper scale

An azotometer (also known as a nitrometer ) is a device for measuring the nitrogen content of combustion gases of organic and ammonium- containing compounds. Different versions of azotometers were made. But there are also azotometers for other applications, for example ureometers to determine the urea content (stoichiometrically convertible to nitrogen content) in urine .

The usual arrangement consists of a gas-tight burette , which is connected to a gas collecting vessel and a level compensation vessel, or a corresponding combined glass apparatus . The azotometer is filled with high-purity potassium hydroxide solution, which absorbs other gases ( carbon dioxide , sulfur dioxide and water) produced during combustion . The resulting nitrogen gas is determined using a scale at the top of the burette.

history

Scan from Liebig's concise dictionary of pure and applied chemistry

The azotometer was developed by Wilhelm Knop as a volumetric measuring device for the nitrogen produced during the oxidation of ammonia with hypochlorous acid in an alkaline medium.

It was used to investigate the nitrogenous fertilizer content in agricultural soils according to the method of A. Wolf.

Nitrogen in the form of primary amines in proteins or their hydrolysates can also be determined azotometrically using the method of Donald Van Slyke (1911). To do this, the proteins / amino acids are diazotized with nitrous acid and the resulting nitrogen is determined volumetrically.

etymology

The term azotometer comes from the French word azote ( "Nitrogen") and the ancient Greek ἀ ( "no") and ζωή ( zoe ) ( "life"). The nitrogen was named by Lavoisier , who saw it as that part of the air that cannot support life.

literature

  • W. Knop: About azotometry and azotometer . Fresenius' Journal of Analytical Chemistry, 25 (1), 1886, 301-308, doi: 10.1007 / BF01335442

Web links

Wiktionary: Azotometer  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ DJ Warner et al .: The Queen Catalogs , 1887 ( Google Books ).
  2. ^ Wissenschaft-online: Entry in the Lexikon der Chemie , accessed on October 3, 2008.
  3. ↑ Liebig, Poggendorff et al. Fehling .: Concise dictionary of pure and applied chemistry , 1861, p. 295 ( Google Books ).
  4. ^ W. Knop .: Chemisches Zentralblatt , 1860, p. 248 u. 257 cited in ( Google Books) .
  5. ↑ A. Wolf. Chem. Centralblatt , 1863, p. 651 u. Journ. f. Prakt. Chem. Vol. 89 , p. 89, quoted in ( Google Books ).