GC Analysis of Pesticide Residues in Hops on SLB®-5ms after QuEChERS Extraction then QuEChERS Cleanup using Supel™ QuE Verde

GC Analysis of Pesticide Residues in Hops on SLB®-5ms after QuEChERS Extraction then QuEChERS Cleanup using Supel™ QuE Verde

Conditions

sample preparation Solid Phase Extraction (Dispersive (QuEChERS))
sample preparation place supernatant in amber low adsorption vial for GC/MS/MS analysis.
sample/matrix Ground hop pellets, 1 gm, spiked at 50 ng/g.
extraction tube Supel QuE Citrate (EN) Tube (55227-U)
extraction process Add 10 mL water to sample, allow to sit for 30 min. Grind 1 g of sample. Add 10 mL water to sample, allow to sit for 30 min, then add 10 mL of acetontrile containing 1% acetic acid. (shake 10 min at 2500 rpm on automated shaker; add contents of Supel QuE Citrate extraction tube; shake 1 minute; centrifuge at 5000 rpm for 5 min; remove supernatant)
clean-up process transfer 1 mL of supernatant to the cleanup tube; shake for 2 min; centrifuge at 5000 rpm for 5 min; remove supernatant
clean-up tube Supel QuE Verde cleanup tube, 2 mL (55447-U)
column SLB-5ms, 30 m x 0.25 mm I.D. x 0.25 µm (28471-U)
oven 50C (2 min), 8C/min to 320C (5 min)
carrier gas helium, 1.4 ml/min constant flow
injection 1 µL, splitless (splitter open at 0.75 min)
liner 4 mm I.D. FocusLiner with taper
inj. temp. 250 C
detector MS/MS
MSD interface 320 C

Description

Analysis Note There are a variety of pesticides used in the commercial production of hops. A standard approach to analysis of pesticides residues is “quick, easy, cheap, effective, rugged and safe” (QuEChERS) extraction followed by highly sensitive LC/MS/MS and/or GC/MS/MS analysis. To maintain the integrity of this type of instrumentation, some form of cleanup is recommended after sample extraction. Hops contain essential oils, acids, pigments, and other compounds that present potential interferences. A standard approach to cleanup of hop extracts is the use of a PSA/C18/GCB sorbent blend. PSA, which stands for "primary-secondary amine" removes acidic interferences while C18 removes hydrophobic interferences. GCB, which stands for "graphitized carbon black" removes pigment. The compounds most effectively removed by GCB have planar structures. Any targeted pesticides with planar structures can also be retained. In this application, a new sorbent blend, Supel QuE Verde, is used for QuEChERS cleanup in the analysis of pesticide residues in hops. Supel QuE Verde consists of PSA, Z-Sep+ and an improved GCB, which provides better recoveries of planar pesticides than traditional GCBs. When used to clean samples containing chlorophyll, Supel QuE Verde will provide better recovery of planar pesticides than blends containing traditional GCB.
Categories Analytical Chromatography, GC Applications, Pesticides
Featured Industry Agriculture
Food and Beverages
Legal Information Supel is a trademark of Sigma-Aldrich Co. LLC, SLB is a registered trademark of Sigma-Aldrich Co. LLC
suitability application for GC, application for SPE

Materials

     
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