# Commission Regulation (EEC) No 2568/91 of 11 July 1991 on the characteristics of olive oil and olive-residue oil and on the relevant methods of analysis, Division 4: REAGENTS

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

4.1. Potassium hydroxide minimum titre 85 %.
4.2. Potassium hydroxide ethanolic solution, approximately 2 M.
Dissolve 130 g of potassium hydroxide (4.1) with cooling in 200 ml of distilled water and then make up to one litre with ethanol (4.9). Keep the solution in well-stoppered dark glass bottles and stored maximum 2 days.
4.3. Ethyl ether, for analysis quality.
4.4. Potassium hydroxide ethanolic solution, approximately 0,2 M.
Dissolve 13 g of potassium hydroxide (4.1) in 20 ml of distilled water and make up to one litre with ethanol (4.9).
4.5. Glass 20x20 plates coated with silica gel, without fluorescence indicator, thickness 0,25 mm (commercially available ready for use).
4.6. Acetone, for chromatography quality.
4.7. n-Hexane, for chromatography quality.
4.8. Ethyl ether, for chromatography quality.
4.9. Ethanol of analytical quality.
4.10. Ethyl acetate of analytical quality.
4.11. Reference solution for thin-layer chromatography: cholesterol, phytosterols, alcohols and Erythrodiol 5 % solution in Ethyl acetate (4.10).
4.12. Solution of 2,7-dichlorofluorescein, 0,2 % in ethanolic solution. Make slightly basic by adding a few drops of 2 M alcoholic potassium hydroxide solution (4.2).
4.13. n-Hexane (4.7)/ethyl ether (4.8) mixture 65:35 (V/V).
4.14. HPLC mobile phase n-hexane (4.7)/ethyl ether (4.8) (1:1) (V/V).

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Source: https://www.legislation.gov.uk/eur/1991/2568/annex/XIX/part/2/division/4 (the official version)
Page: https://openlegislation.uk/eu-regulation-1991-2568/annex-XIX/part-2/division-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.