Multi-Residue Analysis of Pesticides in Flour Using AOAC QuEChERS Method by GC-MS

This application brief demonstrates multi-residue analysis of pesticides in flour using AOAC QuEChERS method by GC-MS.

Extraction Procedure

1. Add 15 mL 1% acetic acid in acetonitrile into the 50 mL DisQuE extraction tube 1.
2. Diluted 5 g flour with 10 mL water and soak for 10 min.
3. Add sample into the 50 mL tube.
4. Add any internal standards and standard mixture.
5. Shake vigorously for 1 minute and centrifuge > 1500 rcf for 5 minute.
6. Transfer 1 mL of the acetonitrile extract into the clean-up tube 2.
7. Shake for 30 seconds and centrifuge >1500 rcf for 1 minute.
8. Transfer 0.5 mL extract into a tube.
9. Add any post-extraction internal standards.
10. Add 0.25 mL toluene.
11. Evaporate at 50 °C with N₂ to < 0.1 mL.
12. Bring volume up to 0.2 mL with toluene.