QuEChERS

QuEChERS, which stands for Quick, Easy, Cheap, Effective, Rugged, and Safe, is a sample preparation method developed in 2003 by a collaboration between the United States Department of Agriculture (USDA) and the Netherlands Food and Consumer Product Safety Authority (NVWA). The technique was originally designed for the extraction of pesticide residues from fruits and vegetables but has since been adapted for a broad range of analytes, including mycotoxins, veterinary drug residues, and environmental contaminants.

The core of the QuEChERS method involves mixing a homogenized food sample with an acetonitrile-based extraction solvent, followed by an addition of a dispersive salting-out mixture containing magnesium sulfate, sodium chloride, and, in some protocols, a pH modifier such as citrate. The sample is then vortexed and centrifuged, yielding a solvent layer that contains the analytes of interest. For cleanup, a dispersive solid‑phase extraction (dSPE) step is typically performed, using sorbents such as primary secondary amine (PSA) or C18 to remove matrix interferences before chromatographic analysis.

The appealing attributes of QuEChERS—low reagent use, minimal equipment, rapid turnaround, and compatibility with high‑throughput liquid chromatography‐mass spectrometry (LC‑MS/MS) and gas chromatography‑mass spectrometry (GC‑MS)—have led to widespread adoption in routine monitoring laboratories worldwide. The method complies with international regulatory frameworks, including the European Union’s “EU Directive 2002/657/EC” and the U.S. Environmental Protection Agency’s “Guidelines for the Development of Dietary Exposure Assessment Models.”

Limitations of QuEChERS include its less effective performance for highly polar or volatile compounds and the need for method optimization for each matrix type. Nevertheless, ongoing refinements, such as the use of mixed sorbents and alternative extraction solvents, continue to expand its applicability across analytical chemistry and food safety disciplines.