Commission Regulation (EC) No 606/2009 (repealed)Show full title

Appendix 4 Ion exchange resins

The ion exchange resins which may be used accordance with paragraph 20 of Annex I A are styrene and divinylbenzene copolymers containing sulphonic acid or ammonium groups. They must comply with the requirements laid down in Regulation (EC) No 1935/2004 of the European Parliament and of the Council(1) and Community and national provisions adopted in implementation thereof. In addition, when tested by the analysis method laid down in paragraph 2, they must not lose more than 1 mg/l of organic matter into any of the solvents listed. They must be regenerated with substances permitted for use in the preparation of foodstuffs. U.K.

These resins may be used only under the supervision of an oenologist or technician and in installations approved by the authorities of the Member States on whose territory they are used. Such authorities shall lay down the duties and responsibility incumbent on approved oenologists and technicians.

Analysis method for determining the loss of organic matter from ion exchange resins:

1. SCOPE AND AREA OF APPLICATION U.K.

The method determines the loss of organic matter from ion exchange resins.

2. DEFINITION U.K.

The loss of organic matter from ion exchange resins. The loss of organic matter is determined by the method specified.

3. PRINCIPLE U.K.

Extracting solvents are passed through prepared resins and the weight of organic matter extracted is determined gravimetrically.

4. REAGENTS U.K.

All reagents shall be of analytical quality. U.K.

Extracting solvents.

4.1. Distilled water or deionised water of equivalent purity. U.K.

4.2. Ethanol, 15 % v/v. Prepare by mixing 15 parts of absolute ethanol with 85 parts of water (paragraph 4.1). U.K.

4.3. Acetic acid, 5 % m/m. Prepare by mixing 5 parts of glacial acetic acid with 95 parts of water (paragraph 4.1). U.K.

5. APPARATUS U.K.

5.1. Ion exchange chromatography columns. U.K.

5.2. Measuring cylinders, capacity 2 l. U.K.

5.3. Evaporating dishes capable of withstanding a muffle furnace at 850 °C. U.K.

5.4. Drying oven, thermostatically controlled at 105 ± 2 °C. U.K.

5.5. Muffle furnace, thermostatically controlled at 850 ± 25 °C. U.K.

5.6. Analytical balance, accurate to 0.1 mg. U.K.

5.7. Evaporator, hot plate or infra-red evaporator. U.K.

6. PROCEDURE U.K.

6.1. Add to each of three separate ion exchange chromatography columns (paragraph 5.1) 50 ml of the ion exchange resin to be tested, washed and treated in accordance with the manufacturer’s directions for preparing resins for use with food. U.K.

6.2. For the anionic resins, pass the three extracting solvents (paragraphs 4.1, 4.2 and 4.3) separately through the prepared columns (paragraph 6.1) at a flow rate of 350 to 450 ml/h. Discard the first litre of eluate in each case and collect the next two litres in measuring cylinders (paragraph 5.2). For the cationic resins, pass only solvents referred to in paragraphs 4.1 and 4.2 through the columns prepared for this purpose. U.K.

6.3. Evaporate the three eluates over a hotplate or with an infrared evaporator (paragraph 5.7) in separate evaporating dishes (paragraph 5.3) which have been previously cleaned and weighed (m0). Place the dishes in an oven (paragraph 5.4) and dry to constant weight (m1). U.K.

6.4. After recording the constant weight (paragraph 6.3), place the evaporating dish in the muffle furnace (paragraph 5.5) and ash to constant weight (m2). U.K.

6.5. Calculate the organic matter extracted (paragraph 7.1). If the result is greater than 1 mg/l, carry out a blank test on the reagents and recalculate the weight of organic matter extracted. U.K.

The blank test shall be carried out by repeating the operations referred to in paragraphs 6.3 and 6.4 but using two litres of the extracting solvent, to give weights m3 and m4 in paragraphs 6.3 and 6.4 respectively.

7. EXPRESSION OF THE RESULTS U.K.

7.1. Formula and calculation of results U.K.

The organic matter extracted from ion exchange resins, in mg/l, is given by:

500 (m1 – m2)

where m1 and m2 are expressed in grams.

The corrected weight (mg/l) of the organic matter extracted from ion exchange resins is given by:

500 (m1 – m2 – m3 + m4)

where m1, m2, m3 and m4 are expressed in grams.

7.2. The difference in the results between two parallel determinations carried out on the same sample must not exceed 0,2 mg/l. U.K.

(1)

OJ L 338, 13.11.2004, p. 4.