# Commission Regulation (EEC) No 1764/86 of 27 May 1986 laying down minimum quality requirements for products processed from tomatoes under the production aid scheme, Division 4.2.2: Dry ashing

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

Weigh out 5 to 10 g of sample, according to assumed quantity of calcium, into a platinum dish (3.2).
Dry in muffle furnace or on hot place or under infra-red lamp, on a gentle, slow heat to avoid losing matter through boiling over. Place residue in muffle furnace preheated to 400 °C and incinerate for at least six hours.
If cadmium is present, a few drops of phosporic or sulphuric acid should be added.
If the ash is not completely white, it should be wetted with a few drops of nitric acid, the product should be dried completely under the infra-red lamp until there are no more white fumes, and treatment in the muffle furnace should be repeated for at least four hours.
Mix the ash with 1 ml nitric acid, transfer to the 50 ml volumetric flask and make up to the mark with water.

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Source: https://www.legislation.gov.uk/eur/1986/1764/annex/division/9/division/4/division/4.2/division/4.2.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-1986-1764/annex/division-9/division-4/division-4.2/division-4.2.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.