# 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 5.2: Calibration curve

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

Remove volumes of 1, 2, 4, 5 and 10 ml of the urea solution (3.5), place in 100 ml volumetric flasks and make up the volume with water. Remove 5 ml from each solution, add 5 ml of 4-DMAB solution (3.1) to each of them, homogenise and measure the optical density as shown above in comparison with a control solution containing 5 ml of 4-DMAB and 5 ml of water free from urea. Plot the calibration curve.

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Source: https://www.legislation.gov.uk/eur/2009/152/annex/III/division/D/division/5/division/5.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-152/annex-III/division-D/division-5/division-5.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.