Malachite Green & Crystal Violet Residues in Shrimp(Copure® ALN Neutral Alumina Cartridges)

Malachite green and crystal violet, once widely used inaquaculture for their low cost and antibacterial properties,can pose health risks due to their toxicity and accumulationin organisms.

Biocomma established a UPLC-MS/MS method for detectionof malachite green and crystal violet in shrimp by Copure®ALN Neutral Alumina Cartridges with good recovery andprecision for your reference. The recoveries were 90-110%with RSD less than 5%.

Experiment

Extraction

Weigh 5.00 g of ground shrimp into a clean centrifuge tube.Add 400 μL of mixed internal standard (malachite green-d5and leuco-malachite green-d6) and 11 mL of acetonitrile.Extract by ultrasonic treatment for 2.0 min, then vortex at2500 rpm for 5.0 min. Centrifugation at 8000 r/min for 5.0min. Transfer the supernatant to another 50 mL centrifugetube. Repeat the extraction procedures. Combine thesupernatant and dilute to 25 mL by acetonitrile. The sampleis ready for purification.

Purification(Copure® ALN Neutral Alumina Cartridges, 1 g/ 3 mL)

Activation: activate the cartridge by 5.0 mL of acetonitrile.Loading: add the prepared solution to the SPE cartridge.Washing: wash the cartridge by 4.0 mL of acetonitrile.

Elution: evaporate to dryness at 45 °C. Add 1.0 mL ofacetonitrile, and sonicate for 5.0 min. then, add 1.0 mL of 5mmol/L ammonium acetate, and sonicate for 1.0 min. Afterfilter by 0.22 μm filter membrane, the sample is ready forLC-MS/MS analysis.

Preparation of Matrix Blank

Prepare blank sample in the same procedures.

Instrument Conditions

1.Chromatographic Conditions

Instrument: UPLC-MS/MS (Thermo Fisher TSQ Endura)Chromatographic column: Commasil® Coreshell C18 (2.1mm×100 mm, 1.7 μm)Mobile phase: A: water (0.1% formic acid), B: acetonitrile(0.1% formic acid)Flow rate: 0.3 mL/ minColumn temperature: 30 ℃

Injection volume: 10 μL

Table 1. Gradient Elution Program