Tables for
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 3.1, p. 150


P. F. Lindleya

aESRF, Avenue des Martyrs, BP 220, F-38043 Grenoble CEDEX, France

Table| top | pdf |
Commonly used ionic and organic precipitants, adapted from McPherson (1985a[link])

(a) Ionic compounds(b) Organic solvents
Ammonium or sodium sulfate Ethanol
Sodium or ammonium citrate Isopropanol
Sodium, potassium or ammonium chloride 2-Methyl-2,4-pentanediol (MPD)
Sodium or ammonium acetate Dioxane
Magnesium sulfate Acetone
Cetyltrimethylammonium salts Butanol
Calcium chloride Dimethyl sulfoxide
Ammonium nitrate 2,5-Hexanediol
Sodium formate Methanol
Lithium chloride 1,3-Propanediol
  Poly(ethylene glycol) 600–20000 (PEG)
The volatility of solvents such as ethanol and acetone may cause handling problems.
Ammonium sulfate can cause problems when used as a precipitant, since pH changes occur owing to ammonium transfer following ammonium/ammonia equilibrium; this effect has been studied in detail by Mikol, Rodeau & Giegé (1989[link]). Monaco (1994[link]) has suggested that ammonium succinate is a useful substitute for ammonium sulfate.