SN/T 1479-2004Malachite green residues in the import and export of aquatic products (English PDF)

2.1 Inspection lot

Take no more than 10,000 boxes for one inspection lot.

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

2.2 Number of samples

The number of samples is shown in Table 1.

Table 1 Sample quantity

Batch/piece

Frozen product, salt collection Minimum number of samples/piece 150 and below 90 and below 3 151~3200 91~500 5 3201~10000 501~1200 13 - 1201~10000 20

2.3 Sampling method

The number of samples according to 2.2 is randomly selected and opened one by one. Take 500g from each piece as the original sample, the total amount of the original sample is quite a lot.

At 4kg, put it in a clean container, seal it, and send it to the laboratory in time.

2.4 Sample preparation

The edible portion was taken from the extracted original sample and placed in a high-speed tissue masher to be evenly mashed. Mix the minced sample thoroughly and separate About 500 g, as a sample, was placed in a clean container and marked with a mark.

2.5 Sample storage

The sample was stored frozen below -18 °C.

2.6 Warning

Samples should be protected from contamination or changes in residue levels during sampling and sample preparation.

3.1 Method summary

The residue in the sample is extracted with an acetonitrile-acetate buffer mixture. After the acetonitrile is extracted again, the liquid and liquid are distributed to the dichloromethane layer, and finally used.

The propane sulfonic acid solid phase extraction cartridge is used for purification, and the eluent is determined by visible light at the CN liquid chromatography column and the PbO2 post-column derivatization column.

the amount. If necessary, it can be confirmed by liquid chromatography-mass spectrometry/mass spectrometry.

3.2 Reagents and materials

Unless otherwise specified, the reagents were of analytical grade and the water was double distilled water.

3.2.1 Acetonitrile. Pure by liquid chromatography.