# Regulation (EC) No 648/2004 of the European Parliament and of the Council of 31 March 2004 on detergents (Text with EEA relevance), Division 5.4.4: Ion-exchange procedure

Extent: E+W+S+N.I.

Connect the exchange columns so that the cation-exchange column is placed on top of the anion-exchange column. Heat the exchange columns to 50 ° C using thermostatic control. Heat 5 000 ml of the solution obtained in item 5.4.2 to 60 ° C and pass the solution through the exchanger combination at a rate of 20 ml/min. Wash the columns with 1 000 ml hot isopropanol/water mixture (5.3.3).
To obtain the non-ionic surfactants collect the filtrate and filter washings and evaporate to dryness, preferably by means of a rotary evaporator. The residue contains the BiAS. Add deionised water until a defined volume is obtained and determine the BiAS content in an aliquot. The solution is used as a standard solution of non-ionic surfactants for the degradation test. The solution should be kept at a temperature below 5 ° C.

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Source: https://www.legislation.gov.uk/eur/2004/648/annex/VIII/division/5/division/5.4/division/5.4.4 (the official version)
Page: https://openlegislation.uk/eu-regulation-2004-648/annex-VIII/division-5/division-5.4/division-5.4.4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.