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.

2.2.1. Buffer solution pH 10 U.K.

Dissolve 24 g sodium bicarbonate, NaHCO₃ AR, and 27 g anhydrous sodium carbonate (Na₂CO₃) AR in deionised water and dilute to 1 000 ml.

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.

2.2.3. Acidic methylene blue solution U.K.

Dissolve 0,35 g methylene blue AR in 500 ml deionised water and mix with 6,5 ml H₂SO₄ (d = 1,84 g/ml). Dilute to 1 000 ml with deionised water. 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.

2.2.4. Chloroform (trichloromethane) AR freshly distilled U.K.

2.2.5. Dodecyl benzene sulphonic acid methyl ester U.K.

2.2.6. Ethanolic potassium hydroxide solution, KOH 0,1 M U.K.

2.2.7. Ethanol pure, C₂H₅OH U.K.

2.2.8. sulphuric acid, H₂SO₄ 0,5 M U.K.

2.2.9. Phenolphthalein solution U.K.

Dissolve 1 g phenolphthalein in 50 ml ethanol and add 50 ml deionised water while stirring continuously. Filter off any precipitate obtained.

2.2.10. Methanolic hydrochloric acid: 250 ml hydrochloric acid AR and 750 ml methanol U.K.

2.2.11. Separating funnel, 250 ml U.K.

2.2.12. Graduated flask, 50 ml U.K.

2.2.13. Graduated flask, 500 ml U.K.

2.2.14. Graduated flask, 1 000 ml U.K.

2.2.15. Round-bottomed flask with ground glass stopper and reflux condenser, 250 ml; boiling granules U.K.

2.2.16. pH meter U.K.

2.2.17. Photometer for measurements at 650 nm, with 1 to 5 cm cells U.K.

2.2.18. Qualitative grade filter paper U.K.