Chromatography: Automated solid-phase extraction (SPE) for the Environmental Testing Laboratory

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Today’s analytical laboratory is faced with tight deadlines to produce results from testing environmental samples. Too often, solid-phase extraction (SPE) presents a bottleneck in the analytical testing process and may cause poor analyte recoveries and highly variable. Despite advances in analytical instrumentation, sample prep often relies on tedious, manual, and expensive techniques such as liquid-liquid extraction. Sample preparation of environmental water samples can be automated, however.. Use of automated sample preparation addresses the many challenges that laboratories face when preparing samples and can help improve sample processing turnaround times. Chromatography presentation goes with this free on-demand webinar. Link to webinar: https://event.on24.com/eventRegistration/EventLobbyServlet?target=registration.jsp&eventid=832348&sessionid=1&key=7401504685427A0804ABBD1F956E617C&partnerrefthermo=undefined&sourcepage=register

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