Artificial seawater

Artificial seawater (abbreviated ASW) is a mixture of dissolved mineral salts (and sometimes vitamins) that simulates seawater. Artificial seawater is primarily used in marine biology and in marine and reef aquaria, and allows the easy preparation of media appropriate for marine organisms (including algae, bacteria, plants and animals). From a scientific perspective, artificial seawater has the advantage of reproducibility over natural seawater.

Example

The tables below present an example of an artificial seawater preparation devised by Kester, Duedall, Connors and Pytkowicz (1967).[1] The recipe consists of two lists of mineral salts, the first of anhydrous salts that can be weighed out, the second of hydrous salts that should be added to the artificial seawater as a solution.

Gravimetric salts
Salt Molecular weight g kg−1 solution
Sodium chloride (NaCl) 58.44 23.926
Sodium sulfate (Na2SO4) 142.04 4.008
Potassium chloride (KCl) 74.56 0.677
Sodium bicarbonate (NaHCO3) 84.00 0.196
Potassium bromide (KBr) 119.01 0.098
Boric acid (H3BO3) 61.83 0.026
Sodium fluoride (NaF) 41.99 0.003
Volumetric salts
Salt Molecular weight mol kg−1 solution
Magnesium chloride (MgCl2.6H2O) 203.33 0.05327
Calcium chloride (CaCl2.2H2O) 147.03 0.01033
Strontium chloride (SrCl2.6H2O) 266.64 0.00009

While all of the compounds listed in the recipe above are inorganic, mineral salts, some artificial seawater recipes, such as Goldman and McCarthy (1978),[2] make use of trace solutions of vitamins or organic compounds.

Standard

The International Standard for making Artificial Seawater can be found at ASTM International.[3] The current standard is named ASTM D1141-98 (the original standard was ASTM D1141-52) and describes the standard practice for the preparation of substitute ocean water. There are various applications for ASTM D1141-98 including corrosion studies, ocean instrument calibration and chemical processing.

See also

References

  1. Kester, D. R., Duedall, I. W., Connors, D. N. and Pytkowicz, R. M. (1967). Preparation of Artificial Seawater. Limnology & Oceanography 12, 176—179.
  2. Goldman, J. C. and McCarthy, J. J. (1978). Steady-state growth and ammonium uptake of a fast-growing marine diatom. Limnology & Oceanography 23, 695–703.
  3. "Standard Practice for the Preparation of Substitute Ocean Water". ASTM International. Retrieved 16 June 2014.

External links


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