QuEChERS Sample Prep and its Cleanup Effectiveness and Efficiency - PowerPoint PPT Presentation

QuEChERS Sample Prep and its Cleanup Effectiveness and Efficiency – A Look at Sorbents

QuEChERS 1. Extraction of Pesticides With Acetonitrile, MgSO 4 and Salt 2. Dispersive Solid Phase Extraction (dSPE) Cleanup of Interferents Cleanup of Fatty Acids with Cleanup of Cleanup of Sterols and Primary Secondary Amine Pigments with Non-polar interferents GCB with C18 Silica Palmitic Acid Campesterol O H 3 C OH Stearic Acid O H 3 C OH Chlorophyll a

Pigmented Sample Issues Carrot Pea Pineapple Raspberry • Liner Fouling Liner with 50 Injections of • Column Retention Time Spinach Extract after dSPE Shortens cleanup with GCB • Peak Tailing

Spiked spinach QuEChERS extracts (at 625 ng/mL) w/o GCB clean ‐ up (5 μ L PTV injections) Not OK after 100 injections Slide from Steven Lehotay, USDA-ARS

Current Solution – GCB Coumaphos O N S Cl Folpet C Cl Cl O Chlorpyrifos DCBP Chlorpyrifos-methyl N Cl Cl Chlorothalonil Cl N Cl 0.0 20.0 40.0 60.0 80.0 100.0 120.0 Recovery (%)

A New Engineered Carbon Material Effect of Glass Microscope Slide More Reproducible Flow Characteristics Weight on Particle Diameter CarbonX GCB Time to elute 4 mL of After After Before CH2Cl2 from 3 mL SPE Cartridge Time (min) under gravity flow. GCB SPE 1 N= 10. GCB cartridge CarbonX is commercially packed & sourced. Intact particles Crushed Particles after grinding Repeatable and Reproducible Pore Structure 1.2 80 A avg pore 1 Pore Vol (cm 3 /g) 0.8 0.6 0.4 0.2 100 um 0 0 100 200 300 400 Pore Diameter (A)

Color results from 3 cleanup styles Spinach CarbonX GCB w/ Tol GCB Extract Plus

Recovery (%) 100.0 120.0 140.0 160.0 20.0 40.0 60.0 80.0 0.0 Dichlorvos Recoveries from 3 cleanup styles PhenylPhenol Lindane Diazinon Chlorothalonil Chlorpyrifos-methyl Dichlorobenzophenone Chlorpyrifos HeptachlorEpoxide Folpet GammaChlordane AlphaChlordane GCB Toluene GCB CarbonX Plus Dieldrin DDE Ethion EndosulfanSulfate Permethrine Coumaphos

Cleanup Style Affects SIM Baseline CarbonX Plus GCB GCB w/Tol

Cleanup Efficiency – X and Y axis 102 GCB Average Recovery of Pesticides (Normalized to Initial Recoveries) CarbonX Plus 100 98 96 94 92 90 88 0 5 10 15 20 25 30 35 40 45 50 Injection Number

Powdered Botanicals - Extreme Fatty Acid Cleanup Saw Palmetto Uncleaned Saw Palmetto 450 mg PSA added to AOAC Pigmented dSPE Tube

Powdered Botanicals - Extreme Fatty Acid Cleanup Ginkgo Biloba Uncleaned Ginkgo Biloba 250 mg PSA added to AOAC Pigmented dSPE Tube

Recovery (%) 100.0 120.0 20.0 40.0 60.0 80.0 0.0 Good Recoveries After Cleanup Dichlorvos Phenylphenol Atrazine Lindane Diazinon Chlorothalonil Chlorpyrifos ‐ methyl DCBP Chlorpyrifos Heptechlor Epoxide Folpet γ chlordane Saw Palmetto Ginkgo Biloba α chlordane Dieldrin DDE Ethion Endosulfan Sulfate Permethrin Coumaphos

Miniaturize and Automate - ITSP Recovery (%) 100.0 120.0 140.0 20.0 40.0 60.0 80.0 0.0 Dichlorvos Phenylphenol 3. Elute with 100 µL 1% Acetic Acid ACN 2. Inject 100 µL of Sample Extract 1. Condition with 100 µL 1% Acetic Acid ACN Atrazine* Lindane Diazinon Chlorothalonil Chlorpyrifos-methyl DCBP Chlorpyrifos Heptechlor Epoxide Folpet γ chlordane α chlordane Dieldrin DDE Ethion Endosulfan Sulfate Permethrin Coumaphos

Conclusions • Superior QuEChERS Recoveries with Engineered Carbon for GC/MS • Similar Color Removal • Greater than 75% recovery for planar pesiticides • Toluene Unnecessary • Decreased Liner and Column Fouling • Sometimes Extreme Issues Can Necessitate Extreme Cleanup Solutions • Miniaturization Can Assist when Sample Volume is an Issue or Automation is Desired Confidential

Dr. Jon Thompson United Science Prof. Dwight Stoll Gustavus Dr. Chunze Lai Dr. Conor Smith R&D R&D Dr. Li Chen R&D Doug Fryer Product Manager