This Test Guideline describes a method to analyse the solution/extraction behaviour of polymers in water, which uses the flask method with modifications.

Three samples of 10 g of particles of the test substance are weighed into each of three vessels fitted with glass stoppers. 1000 ml of water is added to each vessel. The vessels are tightly stoppered and then agitated at 20 °C normally during a period of 24 hours. Then, the content of each vessel is centrifuged or filtered and the concentration of polymer in the clear aqueous phase is determined by a suitable analytical method. For a direct analysis of the aquous phase one sample size is sufficent. Analysis of the aqueous phase for the total polymeric species is possible either by a sufficiently sensitive method or by vacuum evaporation to dryness of the aqueous extract and spectroscopic or AAS/ICP analysis of the residue. When determination of the solution/extraction behaviour of the polymer consists in determining only the total organic carbon content (TOC) of the aqueous extract, an additional test should be conducted, with two different sample sizes in triplicate, using ten times smaller polymer samples and the same amounts of water as those used in the first test. A gravimetric determination is performed on the undissolved/not-extracted part of the sample.