Multiresidue pesticide analysis of botanical dietary supplements using salt-out acetonitrile extraction, solid-phase extraction cleanup column, and gas chromatography-triple quadrupole mass spectrometry.

Dietary supplements form an increasing part of the American diet, yet broadly applicable multiresidue pesticide methods have not been evaluated for many of these supplements. A method for the analysis of 310 pesticides, isomers, and pesticide metabolites in dried botanical dietary supplements has been developed and validated. Sample preparation involved acetonitrile:water added to the botanical along with anhydrous magnesium sulfate and sodium chloride for extraction, followed by cleanup with solid-phase extraction using a tandem cartridge consisting of graphitized carbon black (GCB) and primary-secondary amine sorbent (PSA).

Multiresidue pesticide analysis of agricultural commodities using acetonitrile salt-out extraction, dispersive solid-phase sample clean-up, and high-performance liquid chromatography-tandem mass spectrometry.

A multiresidue method analyzing 209 pesticides in 24 agricultural commodities has been developed and validated using the original Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure and high performance liquid chromatography-positive electrospray ionization-tandem mass spectrometry (LC-MS/MS) analysis. Using solvent-only calibration standards (SOCSs) and matrix-matched calibration standards (MMCSs), it was demonstrated that a minimal concentration of 5-10 μg/kg (part per billion, ppb) of analytes in matrix is required for the consistent identification of targeted pesticides with two MRM transitions. Method performance was validated by the precision and accuracy results obtained from fortification studies at 10, 25, 100, and 500 ppb and MMCSs.