Some Case Of QuEChERS

The QuEChERS method has the following advantages :(1) high recovery rate, which is greater than 85% for a large number of polar and volatile pesticide varieties;(2) high accuracy and accuracy, can be corrected by internal standard method;(3) a wide range of analyzable pesticides, including polar and non-polar pesticide species, can be used to obtain a good recovery;(4) fast analysis speed, able to complete the processing of 6 samples within 30min;(5) less solvent, less pollution, low price, and no chlorine-containing solvent;(6) it is easy to operate and can be completed well without good training and higher skills;(7) acetonitrile is immediately sealed after being added to the container, so as to reduce its contact with the staff;(8) very few glassware is used in the sample preparation process, and the device is simple.

How to have your cake and eat it?

Sample preparation in food safety is an eternal topic. Let’s get a sense of where it’s going.

Case 1 [gc-ecd analysis, residues of 4 pyrethroid insecticides in green pepper] Is mass spectrometry the only way to detect this? No!No!No!Can you use gas chromatography? That how many existing standards can be used ah. For laboratories without GC-ms /MS, this is the most economical option.
Sample: green pepper
Test target: 4 kinds of pyrethroid insecticide
Purification and detection: mpfc-quechers complex matrix purification column;GC – ECD
Determination results:
– average recovery: 88%~110%
-rsd: 0.4%~8.0% (n=3)
Conclusion: using mpfc-quechers complex matrix purification column, the method can even be transferred to gas chromatography, single quadrupole GC-ms.Users who have not yet added GC-ms /MS can immediately experience the simplicity of the QuChERS method.

Case 2 [pesticide residues in grains: removing pigments, fats, sugars, and vitamins at the same time] The grain is a high-starch matrix, rich in pigments, lipids, sugars, vitamins and other substances, pesticide residue determination of the matrix is also very complex.
Samples: rice, wheat, and corn
Detection Target: more than 100 pesticide residues
Purification and detection: mpfc-quechers high-fat purification column;GC – MS/MS
Determination results:
– in the process of method verification, all pesticides obtained satisfactory linearity, with the regression coefficient (R2) greater than 0.9958
– the average recovery rate of 121 pesticides ranges from 70% to 120%, with RSD less than 20%
-lod and LOQ were 0.1~1.3 and 0.2~4.3 g/kg, respectively
Conclusion: compared with d-spe and SPE methods, high-fat purification with mpfc-quechers can be accomplished in a few seconds without the need for leaching and elution steps. This method has been successfully applied to pesticide detection in market samples.

Some Case Of QuEChERS