Third Commission Directive of 27 September 1983 on the approximation of the laws of the Member States relating to methods of analysis necessary for checking the composition of cosmetic products (83/514/EEC)

6.2.1. Liquid samples U.K.

6.2.1.1. Weigh 5 g of the sample into a 100 ml round-bottom flask. Add 1 ml of a suphuric acid solution (4.8) and evaporate the mixture almost to dryness under reduced pressure at 50 ^oC. U.K.

6.2.1.2. Dissolve this residue in 20 ml of warm water. Transfer into a 100 ml standard flask. Rinse three times with 20 ml of water. Make up to 100 ml with water and mix. U.K.

6.2.1.3. Pipette 5 ml of this solution into a 50 ml separating funnel (5.5). Add 10 ml of Fehling's solution (4.16). Extract the quinolin-8-ol copper complex [oxine copper (ISO)] obtained with three times 8 ml of chloroform (4.3). U.K.

6.2.1.4. Filter and collect the chloroform layers in a 25 ml standard flask (5.2). Make up to the mark with chloroform (4.3) and shake. Measure the optical density of the yellow solution against chloroform at 410 nm. U.K.