Internal Standards and Quality Control Standards

• Single and multiple component standards as specified in EN Method 15662

• Support for GC and HPLC with MS, MS/MS, and selective detectors.

• Ready to use QuEChERS extractions no dilutions necessaryProducts

Restek Quechers - Methodology Overview
Restek On-line Presentation - Slide Show / audio
Product Overview PDF ask for detail Lit . . . reviewed

Tubes for Extraction and Clean-up of Pesticide Residues from Food Products

• Fast, simple sample extraction and cleanup using dSPE

• Fourfold increases in sample throughput

• Fourfold decreases in material cost

• Convenient, ready to use centrifuge tubes with ultra pure, preweighed adsorbent mixes

Quick, Easy, Cheap, Effective, Rugged, and Safe, the QuEChERS ("catchers") method is based on work done and published by the US Department of Agriculture Eastern Regional Research Center in Wyndmoor, PA.(1)
Researchers there were looking for a simple, effective, and inexpensive way to extract and clean pesticide residues from the many varied sample matrices with which they routinely worked.
They had been using the Modified Luke Extraction Method, which is highly effective and rugged, but is both labor and glassware intensive, leading to a relatively high cost per sample. Solid phase extraction also had been effective, but the complex matrices the investigators were dealing with required multiple individual cartridges and packings to remove the many classes of interferences, adding costs and complexity to the process.

A new method would have to remove sugars, lipids, organic acids, sterols, proteins, pigments and excess water, any of which often are present, but still be easy to use and inexpensive.

The researchers developed a simple two-step procedure.
(1)    the homogenized samples are extracted and partitioned, using an organic solvent and salt solution.
Then, the supernatant is further extracted and cleaned, using a dispersive SPE technique. Multiple adsorbents are placed in a centrifuge tube, along with the 1mL of organic solvent and the extracted residues partitioned from step 1.
The contents are thoroughly mixed, then centrifuged, producing a clean extract ready for a variety of GC or HPLC analytical techniques
.(2) Validation and proficiency data for the QuEChERS method are available for a wide variety of pesticides in several common food matrices at www.quechers.com

Using the dispersive SPE approach, the quantity and type of adsorbents can be easily adjusted for differing matrix interferences and "difficult" analytes.
Results from this approach have been verified and modified at several USDA and Food and Drug Administration labs, and the method now is widely accepted for many types of pesticide residue samples.

Restek Q-sep™ products make the QuEChERS approach even simpler. Extraction salts are preweighed and provided with 50mL centrifuge tubes. The dSPE centrifuge tubes, available in 2mL and 15mL sizes, contain magnesium sulfate (to partition water from organic solvent) and PSA* adsorbent (to remove sugars and fatty acids), with or without graphitized carbon black (to remove pigments and sterols) or C18 (to remove nonpolar interferences). Custom products are available by quote request. If you are frustrated by the time and cost involved with your current approach to pesticide sample extraction and cleanup, we suggest you try this simple and economical new method.

Restek has products compliant with AOAC, Multi-miniresidue and European methods.
™Click here for our complete Q-sep QuEChERS product listing.

Did You Know?

• Multiple sorbents are used to remove different types of interferences.

• MgSO_{4 -} removes excess water

• PSA* - removes sugars, fatty acids, organic acids, and anthocyanine pigments

• C18 - removes nonpolar interferences

• Carbone- removes pigments, sterols, and nonpolar interferences

*PSA  - primary and secondary amine exchange material.

Flyer

• Restek QuEChERS Products: Fast, Simple Sample Prep for Multi-Residue Pesticide Analysis, FFFL1183 (622kb  12p PDF

Application Note

• Fast, Simple QuEChERS Extraction and Cleanup of Pesticide Residue Samples,
   08 GNAN1097 (165kb pdf)

• 09 2p Flier FFTS1095

QuEChERS Methodology Instruction Sheets

• Mini-Multiresidue Method, 805-01-001 (175kb pdf)

AOAC Approach,

• 805-01-002 (165kb pdf)

• dSPE Sample Clean-up,
  805-01-003 (175kb pdf)

Posters

• Optimizing Dispersive Solid Phase Extraction and Splitless Injection-Gas Chromatography for QuEChERS Fruit and Vegetable Extracts (90kb pdf)
   

METHODS - links

QuEChERS

• A Mini-Multiresidue Method for the Analysis of Pesticide Residues in Low-Fat Products (91kb pdf)

AOAC Official
Method 2007.01

Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate Gas Chromatography/
Mass Spectrometry and Liquid Chromatography/
Tandem Mass Spectrometry First Action 2007

European method CEN/TC 275 - EN_15662

Foods of plant origin Determination of pesticide residues using GC-MS and/or LC-MS/MS following acetonitrile extraction/
partitioning and cleanup by dispersive SPE  QuEChERS-method
 

We have products for
all of these methods!

QuEChERS Products
Quick Easy Cheap Effective Rugged & Safe

SPE Cleanup Techniques using
Multiple Adsorbents for GC and HPLC

QuEChERS Standards
& SPE Tubes

• QuEChERS Internal Standard Mix for GC/ECD Analysis

• QuEChERS Internal Standard Mix for GC/MS Analysis

• QuEChERS Internal Standard Mix for GC/NPD and LC/MS/MS Analysis

• QuEChERS Internal Standard Mix for LC/MS/MS Analysis

• QuEChERS Quality Control Standards for GC/MS Analysis

• QuEChERS Single-Component Reference Standards

• QuEChERS SPE Tubes for Pesticide Residue Analysis

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