Regulation (EC) No 648/2004 of the European Parliament and of the Council of 31 March 2004 on detergents (Text with EEA relevance) (c. 648)

ANNEX VIII U.K. TEST METHODS AND ANALYTICAL METHODS

2. Determination of anionic surfactants in biodegradability tests U.K.

2.2. Reagents and equipment U.K.

2.2.2. Neutral methylene blue solution U.K.

Dissolve 0,35 g methylene blue AR in deionised water and dilute to 1 000 ml. Prepare the solution at least twenty-four hours before use. The absorbency of the blank chloroform phase, measured against chloroform must not exceed 0,015 per 1 cm of layer thickness at 650 nm.