QuEchERS, A Tool In Pretreatment of Pesticide Analysis
QuEChERS, the abbreviation of Quick, Easy, Cheap, Effective, Rugged, and Safe, is a widely used and effective method because of the variety of pesticides and the detection samples. QuEchERS is widely used in the pretreatment of pesticide analysis due to its high recovery and accuracy, simple operation, and low pollution for a large number of polar and volatile pesticides. It is simply summarized as the process of extraction, purification, and extraction.
The first step is the extraction.
Add 10 ml acetonitrile to the sample containing 10 g, and then add internal standard and shake it. Add 4 g MgSO4, 1 g NaCl, 1 g trisodium citrate hydrate, and 0.5 g disodium citrate hydrate, shake it for 1 minute, then centrifuge the sample for 5 minutes at 3000 U/min.
The second step is purification.
One is the decentralized SPE purification process. Transfer 1 ml supernatant to the centrifugal tube containing 150 mg MgSO4 and 25 mg PSA, shake it for 30 seconds, and then centrifuge for 5 minutes at 3000 U/min. Preserve it in acetonitrile solution containing 5% formic acid. And GC/MS detection, requires conversion solvents.
The other is the extraction column purification process. Elute the PSA and GCB double-layer composite columns with 5 ml toluene and transfer supernatant to the column. And then collect the solvent. Then elute with 6-12 ml 3:1 acetone: toluene solvent, and analyzed by GC/MS after concentration.
How it works
The principle is similar to high-performance liquid chromatography (HPLC) and solid-phase extraction (SPE). It uses the adsorbent filler to interact with the impurities in the matrix to adsorb impurities and achieve the purpose of impurity removal.
QuEChERS extraction salts have anhydrous extraction salts with pre-weigh technology. Among them, the anhydrous magnesium sulfate is used for removing water in the sample matrix. Other buffer salts provide a suitable pH environment in order to ensure a good recovery rate for some pesticides which are sensitive to alkalis. When there are samples with large water content, the buffer salts will take an exothermic reaction with water, and then affect the recovery rate. We can add organic solvent before adding the buffering salts so that local overheating of the samples can be avoided.
QuEChERS extraction salts have many advantages. They are ready to use and all components are pre-weighed, which significantly improves man efficiency in the laboratory. Moreover, they can ensure the reproducibility of the analysis results. Because the QuEChERS extraction salts are fully automatically produced, this completely eradicates deviation which is caused by man sub-packaging. In addition, they can also ensure the recovery rate and sensitivity of the multi-residue analysis.
The extraction salts are specially optimized, and no impurities will cause interference. What is more, there is one obvious advantage that the package of QuEChERS extraction salts is easy to tear. This is convenient for storage and transportation, and also a great reduction in the cost of use. Hawach has four types of QuEChERS kits: QuEChERS extraction salts, QuEChERS dispersive SPE kit, QuEChERS dispersive absorbent, and QuEChERS ceramic homogenizers. Hawach products are suitable for the standard methods, including AOAC Official 2007.01 Method and European EN 15662 Method.