LC/MS/MS Analysis of Neonicotinoid Pesticides in Dandelion Blossoms on Ascentis® Express C18 after Dispersive SPE (QuEChERS) using Supel™ QuE
Materials
analytical column
SPE tube or plate
standard
CONDITIONS
sample preparation
Dispersive (QuEChERS)
sample/matrix
3 g pulverized dandelion blossoms, homogenized in 10 mL water
extraction tube
Supel QuE Acetate extration tube (55234-U)
extraction process
add 25 mL of acetonitrile; add contents of Supel QuE acetate extraction tube; shake immediately for 1 minute; centrifuge at 3400 rpm for 5 minutes
clean-up tube
Supel QuE PSA/C18 tube (55288-U)
clean-up process
Transfer 1 mL of the acetonitrile layer into a Supel QuE PSA/C18 cleanup tube; shake for 1 minute; centrifuge at 3500 rpm for 3 minutes; (draw off 700 uL of supernatant, evaporate to dryness at 50 °C under nitrogen; reconstitute in 200 μL of 50:50 0.1% formic acid:0.1% formic acid in methanol)
column
Ascentis Express C18, 10 cm x 3.0 mm I.D., 2.7 μm particles (53814-U)
mobile phase
[A] 0.1% formic acid in water; [B] 0.1% formic acid in methanol
gradient
30% B from 0 to 5 min; to 100% B in 0.2 min; held at 100% B for 5.3 min; to 30% B in 0.5 min; held at 30% B for 5 min
flow rate
500 μL/min
pressure
3800 psi (262 bar)
column temp.
25 °C
detector
MS, ESI(+), MRM, m/z 203.2/129.2, 271.2/225.0, 292.1/211.0, 256.0/175.2, 250.0/132.0, 223.2/126.0, 253.0/125.8
injection
3 μL
Description
Analysis Note
The advent of the die-off of honey bees due to colony collapse disorder (CCD) has spawned investigation into pesticide exposure as the cause. Neonicotinoids are among the suspected culprits. In this application, the QuEChERS approach using Supel™ QuE was used for extraction and cleanup prior to analysis of seven neonicotinoid pesticides in flower blossoms. Ascentis® Express C18 was chosen due to the high efficiency associated with its Fused-Core® particle, and its relatively low backpressure as compared to sub-2 micron UHPLC columns. This allowed the column to be used in a standard pressure HPLC system with a relatively high concentration of aqueous at the start of the mobile phase gradient.
Legal Information
Ascentis is a registered trademark of Merck KGaA, Darmstadt, Germany
Fused-Core is a registered trademark of Advanced Materials Technology, Inc.
Supel is a trademark of Sigma-Aldrich Co. LLC