# Regulation (EC) No 648/2004 of the European Parliament and of the Council of 31 March 2004 on detergents (Text with EEA relevance), Division 3.3.5: Blank determinations

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

At the same time run a blank determination through the whole procedure with 5 ml methanol and 40 ml water, according to the instructions in 3.3.2. The blank titration should be below 1 ml, otherwise the purity of the reagents (3.2.3, 3.2.7, 3.2.8, 3.2.9, 3.2.10) is suspect, especially their content of heavy metals, and they must be replaced. The blank must be taken into account in the calculation of the results.

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Source: https://www.legislation.gov.uk/eur/2004/648/annex/VIII/division/3/division/3.3/division/3.3.5 (the official version)
Page: https://openlegislation.uk/eu-regulation-2004-648/annex-VIII/division-3/division-3.3/division-3.3.5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.