ß₂-Agonists in Pork and Pig Liver Tissues

This application brief demonstrates ß₂-Agonists in pork and pig liver tissues.

Pretreatment

1. Add 8 mL 0.2 M sodium acetate (pH 5.2) to 2 g of sample. Homogenize and take out supernatant. Add 50 μL β-Glucuronidase/arylsulfatase and hydrolyze at 37 °C overnight.
2. Shake the hydrolysate for 15 minutes. Centrifuge at 5000 rpm for 10 minutes and take out 4 mL supernatant.
3. Add 100 μL of 10 ng/mL standards (clenbuterol-D₉, salbutamol-D₃) and mix.
4. Add 5 mL 0.1 M perchloric acid and adjust pH to 1 ± 0.3.
5. Centrifuge at 5000 rpm for 10 minutes.
6. Collect supernatant and add 10 M sodium hydroxide to adjust pH to 11.
7. Add 10 mL saturated sodium chloride and 10 mL isopropanol-ethyl acetate (60:40, v/v).
8. After centrifugation, take organic layer and evaporate to dryness at 40 °C under nitrogen gas.
9. Dissolve residue in 5 mL 0.2 M sodium acetate (pH 5.2).

Pig liver tissues were spiked with 11 β₂-agonists standard mixture of concentrations 0.5 ng/g, 1 ng/g and 2 ng/g respectively. The SPE recoveries are between 89.4% and 110.5%, RSD are between 1% and 2.8%.