Extraction, Cleanup, and Gas Chromatography/Mass Spectrometry
Chromatography: Automated solid-phase extraction (SPE) for the Environmental Testing Laboratory
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Transcript of Chromatography: Automated solid-phase extraction (SPE) for the Environmental Testing Laboratory
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The world leader in serving science
Aaron Kettle
Product Manager – Thermo Fisher Scientific, Automated SPE Systems
9/24/2014
Automated SPE for the Environmental Testing Laboratory
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The Challenge for Analysis
1.5 mL GC / LC Vial
How do we get analytes out of these samples?
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The Answer is Sample Preparation
• Extraction• Removes analytes from the sample
• Eliminates compounds that interfere with the analysis (Clean Up)
• Evaporation• Concentrates extracted analytes for analysis
• Evaporates extracted samples for re-constitution
• Most time consuming part of analytical procedure (>60%)*
• Single largest source of errors in the workflow (>30%)**
*Majors, R.E. LC-GC, 1995, 13, 742-749, and **Majors, R.E. LC-GC, 1999, 17, S8 - S13
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Analysis Techniques!
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Analysis Techniques!
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Sample Preparation…
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Sample Preparation…
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The Important Parameters for Sample Preparation
• Solvent Use• Amount of solvent consumed for the extraction
• Solvents are expensive; reducing use reduces costs
• Extraction Time• Amount of time required for each extraction to occur
• Reducing extraction time increases lab throughput
• % Recovery• Amount of analyte recovered following the extraction
• Low % recovery yields poor analytical results
• % Relative Standard Deviation (RSD) • Measure of reproducibility between extractions
• Extraction results have greater reproducibility with lower %RSDs
These Parameters Evaluate SP Techniques
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Solid-Phase Extraction (SPE)
• SPE is one of the simplest, most cost-effective and versatile methods of sample preparation
• SPE has been widely used in many environmental and food laboratories prior to analysis with GC & GC/MS or LC & LC/MS
• SPE is primarily performed with inexpensive vacuum pumps, manifolds, and choices of many low-cost, prepackaged, disposable cartridges or disks.
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Why is SPE Used?
Concentration
Increases detector sensitivity and improves detection limits
Clean Up
Removes interferences prior to the analytical techniqueMatrix Removal
Removes matrix and elutes the sample into a solvent compatible with the analytical technique
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SPE vs. Liquid-Liquid Extraction (LLE)
• Subject to emulsion formation
• Incomplete phase separations
• Poor analyte recoveries
• Uses expensive breakable glassware
• Uses great volumes of solvent
• Must evaporate large volumes of solvent
• Faster and decreases solvent use
• Can be automated
• More efficient extraction
• Many SPE phases to accomplish greater separation
• No emulsions
Thermo Scientific™ Dionex™ SolEx ™ SPE Cartridges
Separatory Funnel used for LLE
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The Process of SPE
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Dionex SolEx SPE Sorbent Substrates
Silica-Based Sorbents Polymeric Sorbents
Silica substrate with bound functional group
Functional group imparts retentive properties
Named for character of the functional group (e.g. C18)
Styrene-divinyl benzene copolymers that can be modified to create ion exchangers through animation or sulfonation
High-capacity particles (800 m2/g) with narrow size (22 µm) to produce highly efficient low back-pressure extractions
Activated Carbon
High surface area (1000 m2/g) ensures retention of multiple analytes simultaneously
High capacity particles (60 µm) ensures efficient retention in more challenging matrices (e.g. waste water)
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Thermo Scientific Dionex AutoTrace 280 SPE Instrument
The Thermo Scientific™ Dionex™ AutoTrace 280 SPE instrument provides reliable automated SPE for analytical chemists determining organic pollutants in large-volume aqueous samples. Unlike traditional methods such as liquid-liquid extraction using separatory funnels, the Dionex AutoTrace 280 SPE instrument saves time, solvent and labor ensuring high reproducibility and productivity for analytical laboratories. The unit can process up to 6 samples in 2-3 hours.
47 mm Disk System Cartridge (1, 3 or 6 mL) System
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Dionex AutoTrace 280 SPE: For Liquid Samples
• Reduced sample extraction cost• Solvent consumption (up to 90% less than LLE)
• Labor cost (15 min operator intervention)
• Improved productivity• 6 samples loaded onto cartridges in 15 min
• Improved analytical precision• Automated sample loading and elution
• Positive pressure displacement
6 mL Cartridge System
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Pesticide Recovery Study
Dionex AutoTrace 280 SPE instrument Produces Higher Recoveries than Vacuum Manifold
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Dionex AutoTrace 280 SPE Instrument
Analytes Determinative Step Matrix Application Note
Polyaromatic Hydrocarbons (PAHs) GC-MS Surface Water AN 876
Dioxins and Furans GC-MS Surface Water AB 805
Polychlorinated Biphenyls (PCBs) GC-ECD Surface Water AB 805
Endocrine Disruptors GC-MS Surface WaterDrinking Water AB 801
Semivolatile Organic Compounds GC & GC-MS Drinking Water AN 819
Organochlorine Pesticides GC-ECD Drinking Water AN 1004
Sex Hormones HPLC-UV Drinking Water TN 148
Tricolsan HPLC-UV Drinking Water AN 1081
Explosives HPLC-UV Ground Water AN 358
Linear Alkyl Benzene Sulfonate HPLC-UV Waste Water AN 1080
Organophosphorous Pesticides GC-NPD Drinking Water Pending Publication
Visit thermoscientific.com/samplepreparation
Key Applications Summary
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U.S. EPA SPE 500 Methods
EPA Method Analytes Extraction and Analytical Methods Chemistry Used
506 Phthalate and Adipate Esters SPE and GC/PID C18
507 N and P containing Pesticides SPE and GC C18
508.1 Chlorinated pesticides, herbicides and organohalides SPE and GC-ECD C18
521 Nitrosamines SPE and GC/MS/MS Carbon
522 Dioxane SPE and GC/MS Carbon
525.2 Semivolatile Organic Compounds (SVOC) SPE and GC/MS C18
525.3 Semivolatile Organic mpounds (SVOC) SPE and GC/MS C18
526 Semivolatile Organic in DW SPE and GC/MS HRPHS
527 Flame Retardants SPE and GC/MS HRPHS
528 Phenols SPE and GC/MS HRPHS
529 Explosives SPE and GC/MS HRPHS
532 Phenylurea SPE and HPLC C18
535 Acetic Herbicides SPE and LC/MS/MS Graphitized carbon
548 Endothal SPE and GC/ECD C18
539 Hormones SPE and LC/MS/MS HRPHS
553 Benzidines and N containing Pesticides SPE and LC/MS C18
554 Carbonyl compounds SPE and LC C18
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U.S. EPA SPE 600 /1600 Methods
EPA Method Analytes Extraction and Analytical Methods Chemistry Used
606,608, 609, 611, 612 Organochlorine Pesticides and PCB’s SPE and GC/ECD C18
1613 Dioxins and Furans SPE and GC/MS C18
1614 Brominated Diphenyl Ehters SPE and HRGCMS C18
1657 Organophosphorous Pesticides GPC/SPE and GC C18
1668a PCB and congeners SPE and HRGC/HRMS C18
1694 Pharmaceuticals & Personal Care Products SPE and LC/MS/MS HRPHS