Determination of Pesticides Adsorbed on Arthropods and Gastropods by a Micro-QuEChERS Approach and GC-MS/MS.

A miniaturized QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Save) approach combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous determination of nine pesticides (Cyflufenamide, Difenoconazole, Dimethomorph, Fluopicolide, Fluopyram, Metrafenone, Myclobutanil, Quinoxyfen, and Tebuconazole) in insects, snails, and spiders. In contrast to the original QuEChERS approach, only 500 mg of dried and homogenized sample matrix, mixed with 1.0 mL ethyl acetate and 250 mg MgSO:NaCl (4:1), is required for this novel 'micro-QuEChERS' protocol. The organic phase was cleaned using dispersive solid-phase extraction (dSPE) with 75 mg MgSO:PSA sorbent (4:1). The method was validated according to SANCO/12571/2013 and applied to real samples ( n = 7). Fluopicolide was the only detectable pesticide in real samples from vineyards. In two samples, the Fluopicolide levels were between the determined LOD and LOQ (0.15-1.00 mg kg), and in one sample a concentration of 1.68 mg kg was detected. [ABSTRACT FROM AUTHOR]