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QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) is a sample preparation method that was initially developed in 2003 for analyzing veterinary drugs in food. This innovative method was also successfully tested for pesticide residue analysis in plant materials, demonstrating its versatility and effectiveness. The detailed method was published in the journal AOAC International in 2003. Since then, the QuEChERS method has evolved into a widely adopted sample preparation technique used for a variety of analytes across an expanding number of sample types before analysis by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS).
Thermo Scientific QuEChERS kits are designed to streamline your workflow and minimize the potential for error by providing pre-packaged, ready-weighed salts, sorbents, and buffers. These kits are tailored to your specific analytes of interest, sample matrix, and preferred QuEChERS method, ensuring optimal performance and convenience. The available methods include:
✓Original 2003 Method: The foundational method that started it all, providing a robust and reliable approach to sample preparation.
✓AOAC 2007.01 Method: A refined version of the original method, offering enhanced performance for specific analytes and matrices.
✓EN 15662 Method: A European standard method that provides a comprehensive approach to pesticide residue analysis.
✓NY/T 1380-2007 Method: A method tailored to specific regulatory requirements and analytical needs.
Thermo Scientific offers complete packages that include both extraction and clean-up kits, as well as extraction-only and clean-up-only kits to suit your laboratory’s specific sample preparation needs. These pre-packaged kits save time and money, simplify QuEChERS procedures, and ensure high-quality results. By using these kits, you can achieve reproducible results and excellent recoveries for a wide variety of analytes, making your analytical testing more efficient and reliable.
As shown in the workflow diagram below, the QuEChERS method comprises four basic steps:
By following these four basic steps, the QuEChERS method provides a streamlined and efficient approach to sample preparation, enabling reliable and reproducible results for a wide range of analytes.
The original QuEChERS method (Anastassiades et al., 2003) was developed by Steven J. Lehotay and Michelangelo Anastassiades in 2003 for the determination of pesticide residues in fruits and vegetables. This pioneering method was specifically designed to analyze non-base-sensitive compounds and employs a sodium chloride buffer to reduce polar interferences and enhance the efficiency of the extraction process.
Buffering is a critical component of the QuEChERS procedure because it allows for the accurate analysis of pesticides and other residues that display pH dependence in their recoveries, depending on the sample matrix. The buffering process helps to stabilize the pH levels, ensuring that the target analytes are effectively extracted and accurately quantified.
To support the original 2003 QuEChERS method, three different extraction kits are available
Original 2003 method extraction kits | ||||||
|---|---|---|---|---|---|---|
| Part number | Extraction salts | Also includes | Starting sample | Unit size | Purchase | |
![]() | S1-10-ORIG-CH-KIT |
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| 10 g sample | 50/PK | |
![]() | S1-10-ORIG-KIT |
| 50 mL tubes | 10 g sample | 50/PK | |
![]() | S1-10-ORIG-POT |
| ̶ | 10 g sample | 50/PK | |
![]() | S1-15-ORIG-CH-KIT |
|
| 15 g sample | 50/PK | |
![]() | S1-15-ORIG-KIT |
| 50 mL tubes | 15 g sample | 50/PK | |
![]() | S1-15-ORIG-POT |
| - | 15 g sample | 50/PK | |
Chemicals used in the original 2003 method | |
|---|---|
| Acetonitrile: | Used to perform single-phase extraction (SPE) on a sample. Acetonitrile is a polar organic solvent that effectively extracts a wide range of analytes, including pesticides, veterinary drugs, and mycotoxins, from the sample matrix. Its miscibility with water makes it ideal for extracting both polar and non-polar compounds, ensuring comprehensive analyte recovery. |
| Anhydrous MgSO4: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step. This separation is crucial for isolating the analytes in the organic phase. Removes remaining water from the sample during the dispersive solid phase extraction (dSPE) step. Anhydrous magnesium sulfate acts as a drying agent, ensuring that the final extract is free from excess moisture, which could interfere with subsequent analytical steps. |
| NaCl: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step. Sodium chloride helps to increase the ionic strength of the aqueous phase, promoting the partitioning of analytes into the acetonitrile layer. Removes residual water from the sample, enhancing the efficiency of the extraction process. Reduces polar interference and enhances extraction by minimizing the solubility of polar compounds in the aqueous phase, thereby improving the recovery of target analytes in the organic phase. |
| PSA (Primary Secondary Amine): | Used to remove polar matrix components, citric co-extractives, and free fatty acids from the sample during the dispersive solid phase extraction (dSPE) step. PSA is a sorbent that selectively binds to and removes these interfering substances, ensuring that the final extract is clean and suitable for accurate analysis by GC-MS or LC-MS. |
The AOAC 2007.01 QuEChERS Method, developed by Steven J. Lehotay and his co-workers, refines the original 2003 method by incorporating higher concentrations of acetate buffering for enhanced buffering strength. Buffering is essential in the QuEChERS procedure as it stabilizes pH during extraction and clean-up steps, ensuring accurate analysis of pH-dependent pesticides and other residues.
The method starts with homogenizing the sample, such as fruits or vegetables, to achieve uniform consistency. Extraction salts, including magnesium sulfate and sodium acetate, are then added to release analytes into the acetonitrile solvent. The mixture undergoes liquid-liquid partitioning, where anhydrous magnesium sulfate and sodium chloride induce phase separation and remove residual water.
The supernatant is cleaned using dispersive solid phase extraction (dSPE) with sorbents like primary secondary amine (PSA) to remove polar matrix components. The purified extract is then analyzed by GC-MS or LC-MS for precise identification and quantification. Thermo Scientific provides pre-packaged kits to support this method, streamlining workflows and ensuring high-quality, reproducible results.
AOAC 2007.01 method extraction kits | ||||||
|---|---|---|---|---|---|---|
| Part number | Extraction salts | Also includes | Starting sample | Unit size | Purchase | |
![]() | S1-15-AOAC-CH-KIT |
|
|
|
| |
| S1-15-AOAC-KIT |
|
|
|
| |
| S1-15-AOAC-POT |
| ̶ |
|
| |
AOAC 2007.01 method clean-up kits | |||
|---|---|---|---|
| Sample type | Prefilled 2 mL tubes (100/PK) | Prefilled 15 mL tubes (50/PK) | |
![]() Clean-up | General fruits and vegetables | S2-2-GFV-AOAC-KIT
| S2-15-GFV-AOAC-KIT
|
| Pigmented fruits and vegetables | S2-2-P-AOAC-KIT
| S2-15-P-AOAC-KIT
| |
| Fruits and vegetables with fats and waxes | S2-2-FW-AOAC-KIT
| S2-15-FW-AOAC-KIT
| |
| Fruits and vegetables with pigments and fats | S2-2-PF-AOAC-KIT
| S2-15-PF-AOAC-KIT
| |
| All food types | S2-2-ALL-AOAC-KIT
| S2-15-ALL-AOAC-KIT
| |
| Other foods | S2-2-OTH-AOAC-KIT
| S2-15-OTH-AOAC-KIT
| |
| Acetonitrile: | Used to perform single-phase extraction on a sample. It effectively extracts a wide range of analytes, including pesticides, veterinary drugs, and mycotoxins. Its miscibility with water allows for efficient extraction of both polar and non-polar compounds. |
| Anhydrous MgSO4: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step. It removes remaining water from the sample during the dispersive solid phase extraction (dSPE) step, acting as a drying agent to ensure the final extract is free from excess moisture. |
| NaOAc (sodium acetate): | Buffers the sample to stabilize pH. This buffering is essential for maintaining consistent pH levels during the extraction process, ensuring accurate recovery of pH-dependent analytes. |
| PSA (primary secondary amine): | Used during the dSPE step to remove polar matrix components, citric co-extractives, and free fatty acids from the sample, ensuring that the final extract is clean and suitable for accurate analysis. |
| C18: | Removes fats, sterols, and other non-polar interferences from the sample, reducing the presence of non-polar contaminants that could interfere with the analysis. |
| GCB (graphitized carbon black): | Removes pigments from the sample. It is not recommended for use with planar pesticides as it may also remove these target analytes. GCB is particularly effective in cleaning up samples with high pigment content, ensuring a clearer extract for analysis. |
The extraction and clean-up products here support the EN 15662 method. Widely used in Europe, the EN 15662 method was developed by Michelangelo Anastassiades and co-workers, who modified the original 2003 method to use citrate buffering at a relatively low buffering capacity. This variation employs a sodium chloride buffer to minimize polar interferences, along with sodium citrate dihydrate and disodium citrate sesquihydrate buffers. Buffering is a crucial part of the QuEChERS procedure because it stabilizes the pH, allowing for accurate analysis of pesticides and other residues that exhibit pH dependence in their recoveries, depending on the sample matrix. This ensures consistent and reliable results across various sample types.
EN 15662 method extraction kits | ||||||
|---|---|---|---|---|---|---|
| Part number | Extraction salts | Also includes | Starting sample | Unit size | Purchase | |
![]() | S1-10-EN-CH-KIT |
|
| 10 g | 50/PK | |
![]() | S1-10-EN-KIT |
| 50 mL tubes | 10 g | 50/PK | |
![]() | S1-10-EN-POT |
| - | 10 g | 50/PK | |
EN 15662 method clean-up kits | |||
|---|---|---|---|
| Sample type | Prefilled 2 mL tubes (100/PK) | Prefilled 15 mL tubes (50/PK) | |
| General fruits and vegetables
| S2-2-GFV-EN-KIT
| S2-15-GFV-EN-KIT
|
| Pigmented fruits and vegetables | S2-2-P-EN-KIT
| S2-15-P-EN-KIT
| |
| Highly pigmented fruits and vegetables
| S2-2-HP-EN-KIT
| S2-15-HP-EN-KIT
| |
| Fruits and vegetables with fats and waxes
| S2-2-FW-EN-KIT
| S2-15-FW-EN-KIT
| |
Chemicals used in the EN 15662 method | |
|---|---|
| Acetonitrile: | Used to perform single-phase extraction on a sample. It serves as a polar organic solvent that effectively extracts a wide range of analytes, including pesticides and residues, from the sample matrix. Its miscibility with water allows for efficient extraction of both polar and non-polar compounds. |
| Anhydrous MgSO4: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step. Additionally, anhydrous magnesium sulfate removes remaining water from the sample during the dispersive solid phase extraction (dSPE) step, acting as a drying agent to ensure the final extract is free from excess moisture. |
| NaCl: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step and helps to remove residual water from the sample. This step enhances the efficiency of the extraction process by reducing polar interference |
| PSA (Primary Secondary Amine): | Used during the dSPE step to remove polar matrix components, citric co-extractives, and free fatty acids from the sample, ensuring that the final extract is clean and suitable for accurate analysis. |
| C18: | Used to remove fats, sterols, and other non-polar interferences from the sample, reducing the presence of non-polar contaminants that could interfere with the analysis. |
| GCB (Graphitized Carbon Black): | Used to remove pigments from the sample. However, it is not recommended for use with planar pesticides as it may also remove these target analytes. GCB is particularly effective in cleaning up samples with high pigment content, ensuring a clearer extract for analysis. |
The QuEChERS clean-up kit for the NY/T 1380-2007 method is recommended by the China Ministry of Agriculture. This method is designed for the sample preparation of 51 specific pesticide residues in fruits and vegetables, ensuring accurate and efficient analysis by GC-MS. It streamlines the process for reliable results.
NY/T 1380-2007 method clean-up kit | |||
| Sample | Prefilled 15 mL tubes (50/PK) | Purchase | |
|---|---|---|---|
![]() | Fruits and vegetables | S2-15-GFV-NYT-KIT
| |
Chemicals used in the NY/T 1380-2007 method | |
|---|---|
| Anhydrous MgSO4: | Induces phase separation between the water content in the sample and the acetonitrile layer during the liquid-liquid partitioning step. It also removes remaining water from the sample during dispersive solid phase extraction (dSPE). |
| PSA (Primary Secondary Amine): | Used during the dSPE step to remove polar matrix components, citric co-extractives, and free fatty acids from the sample, ensuring a clean extract for accurate analysis. |
| C18: | Employed to remove fats, sterols, and other non-polar interferences from the sample, reducing the presence of contaminants that could interfere with the analytical results. |
LC-MS solution using start-to-finish workflows for quantitation and pesticide residue screening of food
LC-MS solution for routine screening or sensitive quantitation of veterinary drugs and antibiotics in food
Automated, high-throughput workflows for GC and LC automates QuEChERS clean-up of extracts
| Part number | Product description |
|---|---|
Vials & caps | |
| 6ASV9-1P | 2mL clear screw glass vial (9mm short thread) with write-on patch |
| 6ESV9-1PP | 1.5mL clear screw PP vial (9mm short thread) |
| 6ASV9-2P | 2mL amber screw glass vial (9mm short thread) with write-on patch |
| 6ASC9ST1R | Red screw cap (9mm) (PP: white silicone/red PTFE septa: 1.0mm thickness) with AVCS technology |
| 6ASC9ST1 | Blue screw cap (9 mm) (PP: white silicone/blue PTFE septa: 1.0 mm thickness) with AVCS technology |
| Part number | Product description |
|---|---|
Solvents | |
| A956-1 | Thermo Scientific UHPLC-MS grade acetonitrile suitable for LC and GC |
| A458-1 | Thermo Scientific UHPLC-MS grade methanol suitable for LC and GC |
| W8-1 | Thermo Scientific UHPLC-MS grade water suitable for LC and GC |
| A117 | Fisher Chemical Optima LC-MS grade formic acid suitable for LC and GC |
| A115-50 | Fisher Chemical Optima LC-MS grade ammonium formate suitable for LC and GC |
| T00101400 | Thermo Scientific Chromplete acetonitrile suitable for HPLC and GC |
| D1514 | Optima Methylene Chloride for suitable HPLC and GC-MS |
| H3064 | Optima 95% n-Hexane suitable for HPLC and GC-MS |
| S415500 | Sodium sulfate anhydrous suitable for LC and GC |
| Part number | Product description |
|---|---|
HPLC columns | |
| 17326-102130 | Thermo Scientific Accucore aQ (100 × 2.1 mm, 2.6 μm) |
| 071387 | Thermo Scientific Acclaim Trinity P1 (anionic pesticides) (100 × 3.0 mm, 3.0 µm) |
| 17626-102130 | Thermo Scientific Accucore RP-MS (100 × 2.1 mm, 2.6 μm) |
| 17326-102130 | Thermo Scientific Accucore aQ (100 × 2.1 mm, 2.6 μm) |
| Part number | Product description |
|---|---|
GC consumables | |
| 453T2120 | Thermo Scientific LinerGold: Siltek six baffle PTV liner |
| 453A1925UI | SSL splitless liner, single taper, deactivated |
| 26096-1420 | Thermo Scientific TraceGOLD TG-5SIL MS (30 m x 0.25 mm i.d. x 0.25 μm) |
