LC/MS/MS Analysis of Pesticides in Cannabis on the Ascentis® RP-Amide after QuEChERS Extraction and Cleanup Using Supel™ QuE Verde
Materials
analytical column
accessory
Certified Vial Kit, Low Adsorption (LA), 2 mL, pk of 100
volume 2 mL, amber glass vial (with marking spot), natural PTFE/silicone septa (with slit), thread for 9 mmsample prep
solvent
CONDITIONS
sample preparation
Dispersive (QuEChERS)
sample/matrix
1.9 g of cannabis spiked with pesticides at 50 ng/g
extraction tube
Supel QuE Citrate extraction tube (55227-U)
extraction process
add 10 mL of acetonitrile; shake for 30 minutes at 2500 rpm on shaker; add contents of Supel QuE citrate extraction tube; (shake immediately for 1 minute; centrifuge at 5000 rpm for 5 minutes)
clean-up tube
Supel QuE Verde, 2 mL (55227-U)
clean-up process
transfer 1 mL of acetonitrile layer into Supel QuE Verde cleanup tube; shake for 1 minutes; (centrifuge at 5000 rpm for 3 minutes; draw of supernatant for LC/MS/MS analysis)
column
Ascentis RP-Amide, 10 cm x 2.1 mm I.D., 3.0 μm particles (565301-U)
column
Ascentis RP-Amide Supelguard guard cartridge, 2 cm x 2.1 mm I.D., 5 μm particles (565372-U)
mobile phase
[A] 5 mM ammonium formate, 0.1% formic acid in 95:5 water:acetonitrile; [B] 5 mM ammonium formate, 0.1% formic acid in 5:95 water:acetonitrile
gradient
10% B held for 1 min; to 100% B in 13 min; held at 100% B for 6 min; to 10% in 0.5 min; held at 10% B for 6 min
flow rate
0.4 mL/min
column temp.
30 °C
detector
MRM
injection
5 μL
sample
QuEChERS extract of cannabis in acetonitrile
Description
Analysis Note
Consumption of cannabis and/or cannabis based products is currently legal in some form in 28 US states plus the District of Columbia. Pesticide testing on plant material and extracts is required in some states, including Oregon, which mandates a specific target list for testing. A common approach used by testing labs for pesticides is QuEChERS extraction followed by a dispersive cleanup. In this application a majority of the LC-amenable pesticides on the Oregon list were extracted from cannabis spiked at 50 ng/g using QuEChERS, followed by cleanup with Supel™ QuE Verde. Analysis was achieved using the Ascentis® RP-Amide column equipped with a guard. Supel QuE Verde offered sufficient background reduction for LC/MS/MS analysis with recoveries of 70-120% for a majority of the pesticides.
Other Notes
Sample pretreatment: Added 10 mL of deionized water, mixed and equilibrated for 10 minutes
Legal Information
Ascentis is a registered trademark of Merck KGaA, Darmstadt, Germany
Supel is a trademark of Sigma-Aldrich Co. LLC