Rapid detection technology of malachite green and crystal violet in aquatic products (rapid box method)

Malachite green is a green crystal with metallic luster, also known as alkaline green, strict block green, and malachite green

In the past, liquid chromatography was used for the determination of malachite green residues, which was complicated in operation and required professional laboratory personnel.

[Principle of Quick Test]

The malachite green, crystal violet and their metabolites in aquatic products are colorless malachite green and colorless crystal violet.

[Rapid test range]

This method is used to detect malachite green, crystal violet, colorless malachite green, and colorless crystal violet components in fish, shrimp and other aquatic products.

The test materials used in this method were provided by Beijing Zhongwei Food Technology Company and Guangzhou Tianhe Oasis Biochemical Research Center

[Operation method] (according to A quickly in the laboratory, according to B quickly in the field)

(1) Sample processing

A: After the edible part of the aquatic product is minced with a meat grinder, accurately weigh 10.

B: Use scissors to cut about 10g of the sample in a mortar, add a bottle of extractant 2 to grind, and then add a bottle of extractant 1 to continue grinding for 3 to 5 minutes, filter with filter paper, squeeze the residue, and collect 10 mL of the filtrate into 100 mL In the graduated cylinder, dilute the volume to 30mL with steaming water

(2) Chromatographic column activation The chromatographic column is sequentially added with 2 mL of eluent and 5 mL of distilled water before use, pressurize the ear ball, and discard the waste liquid

(3) Connect the 50mL syringe to the chromatography column through the chromatography column, pour the sample solution collected in step (1) into the syringe, pressurize with the injection plug to increase the flow rate, and it is recommended that the time for 30mL sample to pass through the column is 5-8min, wait for the sample solution to drain completely, discard the effluent, and then add 2mL detergent and 2mL distilled water to the chromatography column in sequence, pressurize the ear ball, and discard the waste solution

[Result judgment]

(1) Preliminary results: Observe the color change of the adsorbent in the chromatography column.

(2) For derivatization, sequentially add 2mL eluent and 2mL steaming water to the chromatography column, pressurize the ear ball, discard the waste liquid, pour a bottle of derivatization reagent into the chromatography column, and add 2mL steaming water Use the ear ball to squeeze the water from the upper mouth under pressure; discard the effluent, add the eluate from the centrifuge tube 1 in step (1) to the column, pressurize the ear ball, and collect the effluent with the centrifuge tube 2.

(3) Extraction Take the centrifuge tube 2 in step (2), add 0.

(4) For detection, use a 1 mL syringe to take the lower layer extract in the centrifuge tube 2 in step (3) (be careful not to suck the upper layer liquid), and add it to a hole of the white drip plate.

Related link: Rapid detection of hydrogen peroxide in aquatic products (SFDA law, HX016)