MBAS assay: Difference between revisions
Deleted Orphan hatnote |
specified color reaction |
||
| Line 1: | Line 1: | ||
A '''methylene blue active substances assay''', or '''MBAS assay''', is a [[colorimetric analysis]] [[test method]] that uses [[methylene blue]] to detect the presence of [[anionic]] [[surfactant]]s (such as a [[detergent]] or [[foaming agent]]) in a sample of [[water]]. A surfactant detected by |
A '''methylene blue active substances assay''', or '''MBAS assay''', is a [[colorimetric analysis]] [[test method]] that uses [[methylene blue]] to detect the presence of [[anionic]] [[surfactant]]s (such as a [[detergent]] or [[foaming agent]]) in a sample of [[water]]. A surfactant detected by the [[color reaction]] is called a ''methylene blue active substance'' (MBAS). |
||
After first acidifying a water sample (with [[boric acid]], for example), one adds to it [[chloroform]] and a [[solution]] of methylene blue. Methylene blue is a [[cationic]] [[dye]]. The entire solution is then [[Agitator (device)|agitated]] to distribute these [[reagent]]s throughout the water sample. The color of the water changes according to the amount of surfactants in the sample. The higher the concentration of surfactants, the deeper and richer the blue coloration. |
After first acidifying a water sample (with [[boric acid]], for example), one adds to it [[chloroform]] and a [[solution]] of methylene blue. Methylene blue is a [[cationic]] [[dye]]. The entire solution is then [[Agitator (device)|agitated]] to distribute these [[reagent]]s throughout the water sample. The color of the water changes according to the amount of surfactants in the sample. The higher the concentration of surfactants, the deeper and richer the blue coloration. |
||
Revision as of 21:58, 13 October 2011
A methylene blue active substances assay, or MBAS assay, is a colorimetric analysis test method that uses methylene blue to detect the presence of anionic surfactants (such as a detergent or foaming agent) in a sample of water. A surfactant detected by the color reaction is called a methylene blue active substance (MBAS).
After first acidifying a water sample (with boric acid, for example), one adds to it chloroform and a solution of methylene blue. Methylene blue is a cationic dye. The entire solution is then agitated to distribute these reagents throughout the water sample. The color of the water changes according to the amount of surfactants in the sample. The higher the concentration of surfactants, the deeper and richer the blue coloration.
MBAS assay is a standard technique for detecting anionic surfactants. These include carboxylates, phosphates, sulfates, and sulfonates. An MBAS assay alone does not, however, identify specific surfactants.
References
- Anionic Surfactant Detection
- ASTM D2330 - 02 Standard Test Method for Methylene Blue Active Substances
- Nollet, Leo M. L. Handbook of Water Analysis. 2nd ed. New York: Marcel Dekker, 2007.
- Regulation (EC) No 648/2004 of the European Parliament and of the Council of 31 March 2004 on detergents
See also
 | This article about analytical chemistry is a stub. You can help Wikipedia by expanding it. |