SN/T 1194-2020Testing of genetically modified ingredients in plants and their products Sampling and sample preparation methods (English PDF)

4.1 General rules

4.1.1 The samples taken and prepared should be representative.

4.1.2 Sampling and sample preparation equipment should be clean, dry and free of odor. The materials used in sampling, sample preparation equipment and sample containers should not be treated Contamination caused by sampling.

4.1.3 In order to avoid cross-contamination, use different sampling and sample preparation appliances or equipment to extract and prepare samples of different delivery batches as much as possible.

The container or package containing the sample should be used as a single-use as possible. If this is not possible (for example, when using mechanical sampling equipment), it should be After taking and preparing a sample of the delivery batch, use appropriate methods to clean all utensils and equipment.

4.1.4 During all sampling processes, samples should be avoided from scattering to prevent active organisms from polluting the ecological environment.

4.1.5 Samples should be prepared in physically isolated areas to prevent contamination to other areas or laboratories, and the sample preparation area should be cleaned in time.

4.1.6 When necessary, use DNA destroyers to process sampling and sample preparation utensils and equipment, sample containers and sample preparation areas.

4.1.7 When applicable, the regulations in GB/T 19495.1 shall be referred to to prevent pollution.

4.1.8 Attention should be paid to the protection of samples during sampling. Sampling equipment and sample containers should be stored in a clean environment to avoid rain and dust.

Pollution caused by incoming objects.

4.1.9 All sampling operations should be completed in the shortest possible time to avoid changes in the composition of the samples. If a sampling step requires for a long time, the sample should be stored in an airtight container.

4.2 Batch

4.2.1 Batching of non-propagating materials

4.2.1.1 Batching of non-propagating materials

First, the batch should be approved according to the same contract, the same production batch number, the same variety and grade in the delivery batch. When the delivered batch is less than 10 000 t, the maximum batch size is 500 t. When the delivered batch is greater than 10 000 t, the base is divided into 20 batches based on 10 000 t. For every more than 1 000 t, one batch will be added.

If it is less than 1,000 tons, it will be counted as one batch. Divide the delivered batch by the number of batches as the batch.

Note 1.Example of batch. delivery batch is 600 t, make 2 batches, each batch is 300 t; delivery batch is 13.200 t, make 20 4=24 Batch, each batch is 13 300/24 ~ 555 t.

Note 2.For bulk grains and oilseeds, when the alternative method of Article 8 is adopted, batching is not required.

4.2.1.2 Processed products for batch

The batching of fats and oils shall be carried out in accordance with the provisions of SN/T 0800.1.

Other processed products shall be approved according to the same contract, the same production batch, the same variety, grade or mark.

4.2.2 Propagating material as batch

Plant propagation materials are batched by variety.

6.1 Sampling of non-propagating material

6.1.1 Sampling of bulk raw materials

6.1.1.1 General requirements

Whenever possible, samples should be taken during the movement of goods, such as during cargo handling.

6.1.1.2 Sampling during the movement of goods

The sampling interval shall be determined according to the flow rate of the batch and the goods, randomly select a point in the first interval to draw the first incremental sample, and at this point, incremental samples are taken at a fixed sampling interval.

When taking solid samples, the mechanical sampling equipment used should be able to adjust the amount of incremental samples and sampling frequency within a wide range, and facilitate inspections.

Check and clean. All cargo should have the same opportunity to enter the sampling device of the mechanical sampler. When sampling manually, it should be in accordance with the pre-determined at the sampling interval, take incremental samples from the new section exposed when loading and unloading the goods or from the stopped conveyor belt. When sampling from a stopped conveyor belt, Full bandwidth samples should be taken. When taking samples from the new section of the goods, the upper, middle and lower goods should be taken alternately.

When sampling from a liquid conveying pipeline, separate samples should be taken at a predetermined sampling interval, and the goods to be sampled should be used before sampling.

Clean the sample container.

6.1.1.3 Sampling from cargo containers such as trucks, cabins, silos and containers

Samples should be taken from each cargo container. Calculate the number of samples to be taken from each container in accordance with the quantity and batch of goods contained in the container.

When taking solid samples, should be evenly distributed in the cargo container. If possible, sample the entire depth at each sampling point Product. When it is not possible to sample the entire depth, the stratified sampling method shall be adopted or the sampling method in 5.1.1.2 shall be adopted during the loading and unloading process.

When sampling by stratified sampling, the cargo container should be divided into at least 3 layers. When the cargo volume in the cargo container is more than 3 times the batch size, it should be Layer by batch. First, place samples evenly on the initial surface of the cargo. When the cargo is loaded and unloaded to the middle and lower layers, the surface is evenly distributed to take incremental samples.

6.1.1.4 Sampling from the stockpile

Similar to Article 6.1.1.3, the number of copies is determined according to the quantity and batch of goods in the pile, and the slash method or the sine curve method is used to spread the goods on the pile.

Dot or layered distribution points to take incremental samples.

6.1.2 Sampling of raw materials in bags (boxes)

For the sampling of raw materials in bags (boxes), individual plant samples should be taken from different parts of the bag (box), such as the top, middle and lower parts.

Table 2 determines the number of samples.

6.2 Sampling of propagation material

Random sampling is adopted, and other sampling methods can also be adopted according to needs or circumstances.

7.1 General provisions

The number of samples specified in this standard is limited to the testing of genetically modified products, and the samples obtained are generally not used for other test items. When must when dividing samples, the number of samples should be increased according to the situation.

Article 7.2 gives the minimum number of original samples under normal circumstances, and the minimum number of original samples for processed products is in accordance with the provisions of Article 7.3 Conversion. When there is no genetically modified limit level, the minimum amount of original samples is generally determined based on the genetically modified limit level of 1%. Unit production when the product is large, such as potato, pumpkin, coconut, beet, etc., or the number of particles cannot reach the minimum number given in Article 7.2, press 7.4 the provisions of the article determine the minimum number of original samples.

The minimum number of original samples that should be drawn in each batch should be determined according to the level of genetically modified limit.

Under normal circumstances, the number of samples in each batch should not be less than 50 for uniform batches and 100 for non-uniform batches.

The small quantity and the number of incremental samples determine the incremental sample size, but the incremental sample size shall not be less than the minimum incremental sample size given in 7.5; for processed products, the minimum amount of each batch the number of incremental samples shall not be less than 10, and the minimum amount of incremental samples can be determined based on the minimum quality of the original sample and the number of incremental samples.

7.2 The minimum number of original samples under normal circumstances Normally, the original sample should contain at least the number of units given in Table 3.

Correspondingly, the minimum quality of the original sample can be calculated based on the average grain quality of different varieties of plants or plant products. Table 4 gives the reference value of the minimum quality of the original samples of several grains and oil seeds when the genetically modified limit level is 0.1%.

1 600 000 grains (uneven batch) 560 000 grains (uniform batch) Barley 37mg 59.200g 20 720g Corn 285mg 456 000g 159 600g Oats 32mg 51.200g 17 920g Rape 4mg 6 400g 2 240g Rice 27mg 43.200g 15 120g Soybean.200mg 320 000g 112 000g Wheat 37mg 59.200g 20 720g

7.3 Processed products

The following conversion principles shall be met. when the processed product is converted into its raw material, the minimum number of particles or the minimum mass shall meet the requirements of Table 3 in Article 6.2 or the provisions of Table 4.Since the processing process usually has the effect of homogenization, the minimum quantity corresponding to the uniform batch is generally selected. E.g, when the genetically modified limit level is 0.1%, the minimum quality of the original samples of some products processed from corn and soybeans can be calculated with reference to Table 5.

7.4 Larger goods and small batches of goods per unit product

The unit product is larger...