Dexamethasone in Pork

This application brief describes method to determine dexamethasone in pork.

The European Union (EU) considers dexamethasone residues a high priority in food animals as they are synergistic with illegal growth promoters, such as beta-agonists or anabolic steroids.

Pretreatment

1. Add 5 g of the ground pork into 30 mL of 95:5 acetonitrile:water (v/v).

2. Shake for 20 minutes, homogenize, and shake for 10 minutes.

3. Centrifuge for 5 minutes.

4. Repeat extraction.

5. Combined both extractions and load onto Sep-Pak Vac 3 cc (500 mg), Florisil Cartridges and elute with 30 mL of 95% acetonitrile and bring up to 100 mL with acetonitrile.

6. Take out 20 mL of extract add 10 mL of hexane. Shake for 3 minutes and leave to stand.

7. Take acetonitrile layer and evaporate to dryness.

8. Reconstitute with 4 mL of 0.2 M sodium phosphate buffer (pH 5) to a final volume of 6 mL with water.