About Some Question And Answer For QuEChERS

1. Why does the QuEChERS approach recommend use dry ice or liquid nitrogen homogenizing frozen samples and extracting samples while frozen?
The frozen samples were homogenized with dry ice or liquid nitrogen, and the samples were made into a fine powder (smaller particle size, more homogeneous), thus maximizing the extraction surface area and making the samples easier to process.
Samples should be extracted during freezing to prevent analyte degradation.

2. When I used the QuEChERS method to reconstruct the extract in LC/MS mobile phase solvent, precipitation would occur. How do I get over it?
If sediment is present during reconstruction, it can be ultrasonically treated and centrifuged to see if the sediment has entered the solution. If the recovery solvent is a percentage of methanol in water, first add methanol to dissolve the sample. Ultrasonic treatment and vortex before adding water.

3. Why wasn't the original QuEChERS approach buffered?
The non-buffered was developed for the analysis of fewer pesticides. The buffered is introduced, to apply to larger pesticide screen, and many compounds show pH dependence.

About Some Question And Answer For QuEChERS