SPE (Solid Phase Extraction)
fresh grass clippings spiked with herbicides at 2 ppm
Supelclean LC-SCX, 500 mg/3 mL (57018)
1 mL methylene chloride
2 mL grass extract. Wash with 2 x 2 mL acetonitrile.
Dry packing for 5 min. under nitrogen purge
Dry packing for 5 min under nitrogen purge; wash with 2 x 2 mL DI water
1.5 mL methanol
dilute to 2 mL with DI water
SUPELCOSIL LC-8-DB, 15 cm × 4.6 mm I.D., 5 μm (58347-U) with guard column (59553)
[A] acetonitrile; [B] water; (45:55, A:B)
1.5 mL/min
UV, 254 nm
100 μL
Sample Pre-treatment:
5 g fresh grass clippings spiked with 2 ppm each herbicide. Add 4 g anhydrous sodium sulfate and 20 mL methylene chloride:acetone (80:20). Shake 20 min and allow mixture to stand 1 min.
SUPELCOSIL is a trademark of Sigma-Aldrich Co. LLC
Supelclean is a trademark of Sigma-Aldrich Co. LLC