Studies to improve the extraction yields of incurred pesticide residues from crops using the QuEChERS method.

The influence of various factors on the extraction yields of incurred pesticides from crops using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was thoroughly studied. These factors included extraction time, extraction temperature, agitation approach, and in the case of dry commodities, sample comminution grade. Extraction yields increased with increasing extraction time, eventually reaching a plateau.

Analysis of "Amitraz (sum)" in pears with incurred residues - Comparison of the approach covering the individual metabolites via LC-MS/MS with the approach involving cleavage to 2,4-dimethylaniline.

We developed a method for the hydrolysis of amitraz, and its degradation products 2,4-dimethylphenyl-N'-methylformamidine (DMPF) and 2,4-dimethylformamide (DMF) into 2,4-dimethylaniline (DMA), directly from QuEChERS extracts. The hydrolysis product DMA was analysed using liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) in the positive ion mode with DMA D6 as an internal standard. Validation of DMPF and amitraz via DMA, following hydrolysis directly from the QuEChERS raw extracts, was performed at 0.

QuEChERS-based method for the multiresidue analysis of pesticides in beeswax by LC-MS/MS and GC×GC-TOF.

The validation of an analytical procedure for the determination of pesticide residues in beeswax, an interesting matrix for environmental pollution monitoring, is presented. Using the QuEChERS template, the impacts of wax particle size, sample amount, and cleanup procedure (water addition, dispersive solid phase extraction, freeze-out, and combinations thereof) on extraction yield and coextractive load were studied. Sample preparation through liquid-liquid partitioning between acetonitrile and melted wax (∼80 °C), followed by freeze-out and primary-secondary amine dispersive cleanup, was performed on incurred and pesticide-free samples for 51 residues.

Extracting fumonisins from maize: efficiency of different extraction solvents in multi-mycotoxin analytics.

The complete extraction of analytes is of utmost importance when analyzing matrix samples for mycotoxins. Mycotoxins consist of substances with widely different physicochemical properties; therefore, the loss of toxins that occurs in multi-mycotoxin methods due to compromises in the extraction solvent is currently a topic under discussion. With regard to fumonisins, several extractants from recently published multi-mycotoxin methods were investigated when analyzing unprocessed and processed maize matrices.