# Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed (Text with EEA relevance), Division 3.21: HPLC Mobile phase.

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

Mix 500 ml of acetonitrile (3.1) with 300 ml of ammonium acetate buffer solution (3.18) and 1 200 ml of water (3.14). Adjust the pH to 4,3 using acetic acid (3.5). Filter through a 0,22 μm filter (4.8) and degas the solution (e.g. by ultrasonification for 10 minutes). This solution is stable for one month, if stored in the dark in a closed container.

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Source: https://www.legislation.gov.uk/eur/2009/152/annex/IV/division/D/division/3/division/3.21 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-152/annex-IV/division-D/division-3/division-3.21
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.