The Highlights Of HAWACH QuEChERS Products And Troubleshooting Tips
Now QuEChERS has become the global standard sample processing method for detecting pesticide residues in fruits and vegetables. In addition, its application also involves more and more different fields, such as the detection of antibiotics, drugs, drugs of abuse, and other contaminants in meat, blood samples, wine, and even soil.
QuEChERS method principle
First use a single organic solvent to extract the pesticide in the matrix (if necessary, add an appropriate amount of internal standard), then add the extraction salt to the matrix to oscillate and centrifuge, then use dispersed solid phase extraction, using PSA, C18, Carb and other adsorbents to purify, remove interferences such as fatty acids, pigments, carbohydrates from the components, and finally take the supernatant for analysis after centrifugation.
Highlights of HAWACH QuEChERS products
As a standard sample processing method to detect pesticide residues in fruits and vegetables, QuEChERS has been applied world widely. In addition, its application also involves more and more different fields, such as the detection of antibiotics, drugs, drugs of abuse, and other pollutants in meat, blood samples, wine, and even soil.
The QuEChERS method has the same purification effect as the solid-phase extraction method, but the processing steps are significantly simplified, the amount of solvent is significantly reduced, the data accuracy is greatly improved, and the application range is greatly expanded. It is a high-throughput sample preparation method.
Adhering to the principle of fast and efficient extraction of pesticide residues by QuEChERS technology, HAWACH refers to the American standard (AOAC2007.01), European standard (EN 15662), and has released the salt pack, extraction tube, and purification tube to facilitate the experiment process.
Highlight: Add acetonitrile and a small amount of ammonium sulfate to the sample for efficient and uniform extraction, and then add mixed salt to achieve efficient salting-out phase separation extraction. By doing so, it effectively avoids the loss of pesticide residues caused by the agglomeration, heating, and excessive phase separation of magnesium sulfate.
QuEChERS Troubleshooting Tips
1. Use matrix-matched calibration standards for greatest accuracy;
2. Use internal standards;
3. Samples must be at least 80% hydrated for effective extraction;
4. Adding extraction salts directly onto the sample will reduce recovery. Mix sample with solvent first;
5. Buffering is required for base sensitive compounds;
6. Graphitized Carbon Black (GCB) can reduce planar analyte recovery
-Use HAWACH during extraction to remove chlorophyll
-Use less GCB
-Two-phase (GCB/PSA) column is used and eluting with 3:1 acetone/toluene
7. For GC analysis, solvent exchanging the final extract into toluene prevents the loss of thermally labile and acetonitrile sensitive pesticides such as chlorothalonil;
8. Adding dilute formic acid to the extract after clean-up will prevent degradation of base sensitive compounds while waiting for LC analysis;
9. Do not use HAWACH when extracting mycotoxins. Use end-capped C18 for clean-up.
1. Acetic acid can hinder the clean-up effectiveness of PSA and cause fronting and tailing issues with GC chromatograms. Choose a QuEChERS method without using acetic acid.
2. Cartridge clean-up is used to make a cleaner extract.