Thursday, July 26, 2012

Ammonium Sulphate

  • Ammonium sulfate (IUPAC-recommended spelling; also ammonium sulphate in British English), (NH4)2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen as ammonium cations, and 24% sulfur as sulfate anions.
  • Ammonium sulfate is well known for the firstorder phase transition which occurs upon cooling through 224 K (at room pressure) from a para-electric crystal (space group Pnam, Z=4) to a ferro-electric crystal.
  • Ammonium sulfate is made by treating ammonia, often as a by-product from coke-ovens, with sulfuric acid-2 NH3 + H2SO4 = (NH4)2SO4.
  • Ammonium sulfate is a widely used reagent in molecular biology and chromatography. Applications include the precipitation and fractionation of proteins,purification of antibodies,crystallization of proteins,protein-nucleic acid complexes,and of nucleic acids.Ammonium sulfate is also widely used in HPLC of proteins, such as in hydrophobic interaction chromatography.

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