QuEChERS

QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) is a sample extraction and clean-up technique used for the analysis of multiple pesticide residues in agricultural products. Explore UCT’s QuEChERS kit, a tool to systematically simplify overall method development processes. Through exploiting different mechanisms of interaction, labs will be able to maximize selectivity and improve recoveries for respective analytes of interest. UCT manufactures a wide variety of pre-filled tubes and reagent pouches for all QuEChERS method variations including PSA, C18, buffers, anh. MgSO4, NaCl, ChloroFiltr, and carbon.

In this application note, UCT, Inc. presents a variety of QuEChERS sample preparation and clean-up techniques for the analysis of multiple pesticide residues in agricultural matrices.

This application note details an optimized method for the extraction and cleanup of pesticide residues from coffee using a QuEChERS extraction procedure followed by a silica gel SPE cleanup. Twenty representative pesticides, most of which are commonly used pesticides on coffee farms, were evaluated in this study. GC-MS was used for pesticide detection and quantification.

In this poster, recoveries of seven problematic pesticides in olive oil, including six base sensitive compounds (chlorothalonil, dicofol, dichlofluanid, tolylfluanid, folpet and captan), and one acid sensitive compound (pymetrozine) were determined by a modified QuEChERS procedure using GC/MS in SIM mode. This procedure can be also used for the determination of problematic pesticides in other fatty matrices.

The medical use of marijuana has been legalized in many states in the USA. With this limited legalization and use of marijuana, the determination of pesticide residues becomes important. Patients taking medical marijuana in conjunction with other therapies may be more vulnerable to toxic substances, such as pesticides. This poster presents a robust and efficient method using the AOAC QuEChERS and LC-MS/MS techniques to determine pesticide concentrations in marijuana samples.

This poster presents several applications using modified QuEChERS approaches for unconventional analytes (e.g. bisphenol A and acidic herbicides) and unconventional sample matrices (e.g. soda, milk, red wine and soil). Employment of a number of modifications to the method contributed to good analyte recovery and extract cleanliness for a wide range of matrices and analytes. Analysis was carried out by LC-MS/MS.

Recoveries of seven problematic pesticides in olive oil, including six base sensitive compounds and one acid sensitive compound were determined by a modified QuEChERS procedure using GC/MS in SIM mode. Comparisons of different clean-up methods were also evaluated. PSA/C18 dual layer SPE cartridges provided the best extract clean-up.

This application note describes a screening method for the analysis of 310 pesticides, isomers of organohalogen, organophosphorus, organonitrogen and pyrethroid pesticide metabolites in a variety of dried botanical dietary supplements, spices, medicinal plants, herbals, teas, and phyto- medicines.