SN/T 1017.8-2004Determination of imidacloprid residues in cereals for import and export. Liquid chromatographic method (English PDF)

2.1 Inspection lot

Take no more than 4000 bags (200t) as an inspection lot.

Goods in the same inspection lot should have the same characteristics, such as packaging, marking, origin and grade.

2.2 Number of samples

Calculate the number of sampling bags according to formula (1).

In the formula.

N---the total number of bags;

犪---Number of sampling bags.

Note. The value of is an integer, and the fractional part is an integer to the forward position.

2.3 Sampling tools

2.3.1 Single tube sampler. stainless steel tube, full length 55cm (including handle), diameter 1.5cm ~ 2.0cm, groove length should exceed the diagonal of the bag Half the length of the line.

2.3.2 Sampling shovel.

2.3.3 Sample plate.

2.3.4 Sample tube (bag). can be sealed.

2.3.5 Sample cloth or suitable mats.

2.4 Sampling methods

2.4.1 Reverse packet sampling

Randomly extract 10% of the number of samples to be sampled from each part of the stack (not less than three bags per batch), and stitch all the seams of the bag.

Disassemble, lay flat on the sample cloth or other clean bedding, hold the two corners of the bag with both hands, lift the angle of about 45°, and drag it about 1m to make it inside the bag.

All the goods are dumped. Check that the quality of the bag and the bag are even. After confirming that the situation is normal, use a sampling shovel to randomly take samples from various parts.

Pour the sample into the sample container. The number of samples taken per bag should be basically the same.

2.4.2 Sampling in the bag

According to the 90% of the number of bags to be sampled according to 2.2, the upper, middle and lower layers around the stack are randomly drawn in a curved pattern. Sampler (2.3.1) The tube groove is facing downward, inserted into the bag from the corner of each bag diagonally, then the tube groove is turned upwards, the sampler is taken out, and the sample is immediately taken.

Pour into a sample container. The number of samples taken per bag should be basically the same as 2.4.1.

The total amount of each batch of samples should be no less than 4kg.

2.4.3 Large sample reduction

Collect all the samples in the concentrated bag and the inverted bag sample, pour it on the sample cloth, and use the sample plate to divide the sample by the quarter method to not less than 2kg.

In the sample cylinder, mark it after sealing and send it to the laboratory in time.