QuEChERS is a dispersive solid phase extraction (dSPE) technique utilized in sample preparation. Its acronym, standing for ‘Quick, Easy, Cheap, Effective, Rugged, and Safe,’ was originally created for analyzing pesticide residues in fruit and vegetable samples. Over time, this method has been adapted to examine other chemical classes such as PAHs, PCBs, PBDEs, and flame retardants. Its introduction dates back to 2002, and it is now officially specified in methods by the Association of Analytical Communities (AOAC 2007.01) and the European Committee for Standardization (EN 15662:2008).

QUECHERS SAMPLE EXTRACTION

To maximize analyte yield from the sample matrix, solvent extraction techniques are employed. Water-miscible solvents, typically acetonitrile, along with high salt and buffering agent concentrations, are used to extract the target analytes from the sample. Careful solvent selection is crucial to minimize co-extraction of unwanted compounds. Salts play a vital role in this process by creating phase separation, adjusting the pH, and removing excess water from the sample.

QUECHERS CLEANUP

The goal of sample cleanup in QuEChERS is to reduce interference during subsequent analysis, protecting analytical instrumentation and simplifying the identification and quantification of analytes. Unlike traditional methods using SPE tubes, QuEChERS cleanup involves mixing bulk amounts of SPE sorbents with the sample extract. These sorbents effectively remove matrix interferences that coextract with the target analytes. Depending on the matrix complexity, PSA, C18, GCB (graphitized carbon black), or special Z-Sep sorbents are utilized to eliminate substances like sugars, lipids, sterols, organic acids, proteins, carotenoids, chlorophyll, and pigments before conducting GC-MS/MS or LC-MS/MS analysis.