# Council Decision of 14 November 1992 laying down methods for the analysis and testing of heat-treated milk for direct human consumption (92/608/EEC), Division 6.4: Immediately connect each Kjeldahl flask to a distillation apparatus (5.6.). Ensure that the tip of the condenser outlet-tube is immersed in 50 ml of boric acid solution (4.5.) together with 0,20 ml (5 - 6 drops) of indicator solution (4.6.) all contained in a conical flask (5.8.). Swirl the contents of each Kjeldahl flask to mix thoroughly and boil, but gently at first to prevent excessive frothing. When 100 to 125 ml of distillate have been collected, lower each conical flask until the tip of the condenser outlet-tube is approximately 40 mm above the 200 ml mark. Continue each distillation until irregular boiling (‘bumping’) starts and then immediately stop the heating. Disconnect each Kjeldahl flask and rinse the tip of each condenser outlet-tube with a little water, collecting the rinsings in the conical flask. Note the following requirements:

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

(a) The distillation rate shall be such that approximately 150 ml of distillate are collected when irregular boiling (‘bumping’) starts, the volume of the contents of each conical flask will then be approximately 200 ml.
(b) The efficiency of each condenser should be such that the temperature of the contents of each conical flask does not exceed 25 oC during the distillation.

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Source: https://www.legislation.gov.uk/eudn/1992/608/annex/2/division/IV/division/6/division/6.4 (the official version)
Page: https://openlegislation.uk/eu-decision-1992-608/annex-2/division-IV/division-6/division-6.4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.