Abstract
Vacuum head space solid-phase microextraction (Vac-HS-SPME) could provide an alternative for extracting pesticides from grape samples while minimizing matrix effects. Vac-HS-SPME method is utilized to the simultaneous analysis of six pesticides from various classes, namely boscalid, quizalofop-p-methyl, oxyfluorfen, fluroxypyr, metribuzin and epoxiconazole. We investigated and optimized the impact of independent variables, such as extraction temperature (30-80°C), extraction time (1-40 min), fiber coating (CAR/PDMS/DVB 50/30 µm; PDMS 100 µm; PEG 60 µm), incubation time (1-20 min), salt effect, sample volume (0.25-5 mL) air evacuation time (30-120 s), pH (3-10), desorption time (1-5 min) with the objective of achieving lower detection limits (0.11-1.87 µg mL-1) and effective analyte responses. Gas chromatographic separation was accomplished using a SLB-5ms column. Moreover, in this work a comparison was made between classical solid phase microextraction and vacuum solid-phase microextraction for the extraction of pesticide in grape samples under the same parameters. The results clearly demonstrated that the combination of Vac-HS-SPME proved to be more appropriate and selective for the extraction of pesticides from grapes.