Comparison Between Two Kinds Of QuEChERS Purification Method
As a reliable lab partner, HAWACH focuses on providing faster, simpler, and more convenient experimental solutions and consumables. Its flexible QuEChERS kits, including centrifuge tubes, extraction tubes, purification tubes, and reagent bags of different specifications, are to help you quickly establish standard-compliant detection methods.
Now more and more testers are using the QuEChERS purification method to detect pesticide residues. What are the specific effects of the QuEChERS purification method and Carb / NH2 column purification method on detection?
When mass spectrometry is used, one of the following two purification methods can be selected; when PFPD is used, Carb / NH2 column purification is the best method.
Transfer the combined 30 ml extract of the above acetonitrile extraction sample to a 50 ml centrifuge tube, add 1.5g anhydrous sodium sulfate and 0.5g PSA powder (for vegetable varieties with high-fat content such as beans, etc. And then add 0.25 g C18 solid-phase adsorbent), centrifuge at 5000rpm for 2min after vortexing.
Take the supernatant into a chicken heart bottle, and evaporate to near dryness in a 30°C water bath. Re-dissolve in a 5 ml stoppered test tube with n-hexane, blow to near dryness with nitrogen, dilute to 1 ml with n-hexane, and pass the membrane, which is to be analyzed by GC-PFPD or GC-MS.
Hawach can provide a suitable extraction tube and purification tube with higher quality for you to get better results.
Carb / NH2 column purification
The above sample is reconstituted with acetone: dichloromethane (1:1, volume ratio) to 3 ml in portions, and the Carb / NH2 column is taken and fixed on a suitable shelf. Use 5 ml of acetone: Dichloromethane (1:1, volume ratio) solution is used to rinse the activated small column.
When the liquid level of the mixed solution is about to reach the surface of the adsorption layer of the small column, put the reconstituted extract on the column immediately, and start collecting the effluent.
When the liquid level is about to reach the surface of the adsorption layer of the small column, use 30 ml of acetone: dichloromethane Methane (1:1, volume ratio) elutes; collect all the eluate and the above effluent and combine them in a 30°C water bath to evaporate to near dryness.
Re-dissolve in a 5 ml stopper test tube with n-hexane and blow to near dryness, dilute to 1 ml with n-hexane, filter through a syringe-type microporous membrane and transfer it to a gas chromatography sample bottle for GC or GC-MS analysis.
If you have any questions when using the QuEChERS method, welcome to contact HAWACH(www.hawach.com) to learn more. Its professional team with decades’ experience will surely clear your doubts.