Rapid detection box for hidden peacock green in aquatic products

Rapid detection box for hidden peacock green in aquatic products

Rapid detection box for hidden peacock green in aquatic products

Malachite green (MG) and crystal violet (CV) have the characteristics of high toxicity, high residue, carcinogenicity, teratogenicity, and mutagenicity. When they enter the body, they will produce more harmful hidden Malachite green (LMG) and hidden crystal violet (LCV). Due to the harmful effects of malachite green and crystal violet, many countries, including China, have listed them as banned drugs in aquaculture. This product is suitable for rapid detection of peacock A green, crystal violet, hidden peacock green, and hidden crystal violet in aquatic products.

【 Detection Principle 】

After processing, the extracted solution of malachite green, crystal violet, and their metabolites in aquatic products is enriched in small columns to form colored rings, which can preliminarily determine whether the sample contains malachite green and crystal violet. Wash the analyte on the column with an eluent, derivatize it on the column, and add an extractant. If the extractant has a clear green or purple color, it indicates that the analyte is present in the sample. Take out the extractant and drop it onto a white drip plate, which can form green or purple spots on the plate, thus accurately determining whether the sample contains malachite green or crystal violet.

1. Sample extraction: Take 5 grams of the edible portion of the product (which can be ground with a meat grinder or cut with scissors) and add 10 mL of extraction agent to the sample extraction bottle. Grind for 3 minutes (which can be done with a 10 mL or 5 mL plastic centrifuge tube), filter with filter paper, collect 5 mL of filtrate, and then add 10 mL of distilled water (or purified water) to the filtrate. Mix well and set aside for later use. This is the sample extraction solution.

2. Column activation: Take 1 peacock greenDEAdd 0.8mL of eluent to the small column, pass it through the column (pressurized with an ear wash ball), then add 1.5mL of distilled water, pass it through the column (pressurized with an ear wash ball), discard the effluent, and do not squeeze the column dry.

3. Sample solution passing through the column: Add the sample extraction solution to the column, adding about 1.5mL each time, and use an ear wash ball to squeeze it. The squeezing pressure should be moderate to allow the solution to flow out drop by drop until all the sample extraction solution passes through the column. Squeeze dry and discard the effluent. Then add 3mL of distilled water twice to the small column, wash the column, squeeze the ear wash ball under pressure, and discard the effluent. Observing the color change of the adsorbent in the small column, if the adsorbent gradually forms a green ring, it can be preliminarily judged that the sample contains malachite green; If the adsorbent gradually forms a purple ring, it can be preliminarily determined that the sample contains crystal violet.

4. Elution: Add 3mL of eluent into the small column twice for elution, collect the effluent in a 5mL plastic centrifuge tube, apply pressure with an ear wash ball, and observe the color of the effluent to determine its color.

5. Sample derivatization: Add 0.5mL of eluent to the small column, pass through the column (pressurized with an ear wash ball), then add 1.5mL of distilled water, pass through the column (pressurized with an ear wash ball), discard the effluent, and press the ear wash ball dry. Add 1 tablespoon of derivatization reagent to the small column, add 1.5mL of distilled water (or purified water), and use an ear wash ball to squeeze dry under pressure from the upper opening. Discard the effluent. Add the effluent collected in step (4) into the column in two portions, apply pressure with an ear wash ball, and use another 5mL centrifuge tube to receive the effluent. Before the effluent runs out (keeping the column moist), add 1mL of eluent to the small column, apply pressure with the ear wash ball to squeeze dry, and continue to collect the effluent using this centrifuge tube. Observe the eluent passing through the column and the color change of the adsorbent in the small column. If there is no color change of the adsorbent in step (3), but the adsorbent in the small column turns green at this time, it can be preliminarily judged that the sample contains hidden malachite green.

6. Extraction: Add 0.8mL of extractant to the centrifuge tube collected from the effluent in step (5), close the tube plug, invert the tube plug up and down 10 times (without vigorous shaking), and let it stand. If there is a clear green or purple color in the lower solution of the centrifuge tube, it can be determined that the sample contains malachite green or crystal violet. If there is no clear green or purple color, further judgment is required.

7. Detection: Use a plastic pipette to draw the extraction solution from the lower layer of the centrifuge tube in step (6) (be careful not to draw up the upper layer liquid), immediately add it to a hole in the white drip plate, and the sample solution gradually evaporates. If green spots form on the drip plate, it indicates that the sample contains malachite green, and if purple spots form, it indicates that the sample contains crystal violet.

2.0 μg/kg（2.0ppb）。

【 Precautions 】

1. Malachite green extractant. After extracting the extractant, immediately tighten the bottle cap and seal it to prevent volatilization.

When the reagent comes into contact with the skin, rinse immediately with clean water

Storage conditions and expiration dateThe reagent is stored at room temperature and away from light, with a shelf life of 1 year.