SPE (Solid Phase Extraction)
water spiked with pesticides at 10-50 μg/L
Supelclean ENVI-Carb, 250 mg/3 mL (57088)
5 mL methylene chloride:methanol (80:20); 1 mL methanol; 10 mL 2% acetic acid in water (keep bed moist until sample addition)
100 mL sample at 5 mL/min
1 minute with vacuum
0.8 mL methanol; 2 x 35 mL methylene chloride:methanol (80:20)
dry eluate to 500 μL under gentle nitrogen stream, reconstitute to 1 mL with methanol
SUPELCOSIL LC-18-DB, 25 cm × 4.6 mm I.D., 5 μm particles (58355-U)
[A] water:acetonitrile (90:10), [B] acetonitrile; gradient 80% A for 5 min then to 30% A over 30 min
1.5 mL/min
UV, 220 nm
20 μL
ENVI-Carb is a trademark of Sigma-Aldrich Co. LLC
SUPELCOSIL is a trademark of Sigma-Aldrich Co. LLC
Supelclean is a trademark of Sigma-Aldrich Co. LLC