Commission Regulation (EC) No 152/2009Show full title

A. PREPARATION OF SAMPLES FOR ANALYSIS U.K.

1. Purpose U.K.

The procedures described below concern the preparation for analysis of final samples, sent to the control laboratories after sampling in accordance with the provisions laid down in Annex I.

These samples must be prepared in such a way that the amounts weighed out, as provided for in the methods of analysis, are homogeneous and representative of the final samples.

2. Precautions to be taken U.K.

The sample preparation procedure to be followed is dependent on the methods of analysis used. It is therefore of major importance that it is ensured that the followed sample preparation procedure is appropriate for the used method of analysis.

All the necessary operations must be performed in such a way as to avoid as far as possible contamination of the sample and changes of its composition.

Grinding, mixing and sieving shall be carried out as quickly as possible with minimal exposure of the sample to the air and light. Mills and grinders likely to appreciably heat the sample shall not be used.

Manual grinding is recommended for feed which are particularly sensitive to heat. Care shall also be taken to ensure that the apparatus itself is not a source of contamination of trace elements.

If the preparation cannot be carried out without significant changes in the moisture content of the sample, determine the moisture content before and after preparation according to the method laid down in Part A of Annex III.

3. Procedure U.K.

Divide the sample into adequate subsamples for analysis and for reference by using adequate splitting techniques like alternate shovelling, stationary or rotary riffling. Coning and quartering is not recommended because this might provide subsamples with high splitting error. Keep the sample for reference in a suitable clean, dry container, fitted with an air-tight stopper, and prepare the subsamples for analysis of at least 100 g as indicated below.

3.1. Feed which can be ground as such U.K.

Unless otherwise specified in the methods of analysis, sieve the whole sample through a sieve with a square mesh of 1 mm side (in accordance with recommendation ISO R565) after grinding, if necessary. Avoid any over grinding.

Mix the sieved sample and collect it in a suitable clean, dry container fitted with an air-tight stopper. Mix again, immediately before weighing out the amount for analysis.

3.2. Feed which can be ground after drying U.K.

Unless otherwise specified in the methods of analysis, dry the sample to bring its moisture content down to a level of 8 % to 12 %, according to the preliminary drying procedure described under point 4.3 of the method of determination of moisture mentioned in Part A of Annex III. Then proceed as indicated in section 3.1.

3.3. Liquid or semi-liquid feed U.K.

Collect the sample in a suitable clean, dry container, fitted with an air-tight stopper. Mix thoroughly immediately before weighing out the amount for analysis.

3.4. Other feed U.K.

Samples which cannot be prepared according to one of the above procedures shall be treated by any other procedure which ensures that the amounts weighed out for the analysis are homogeneous and representative of the final samples.

4. Storage of samples U.K.

Samples must be stored at a temperature that will not alter their composition. Samples intended for the analysis of vitamins or substances which are particularly sensitive to light shall be stored in brown glass containers.