QuEChERS and solid phase extraction methods for the determination of energy crop pesticides in soil, plant and runoff water matrices

QuEChERS and solid phase extraction (SPE) methods were applied for determining four herbicides (metazachlor, oxyfluorfen, quizalofop-p-ethyl, quinmerac) and one insecticide ((+/-)-cypermethrin) in runoff water, soil, sunflower and oilseed rape plant matrices. Determination was performed using gas chromatography mass spectrometry (GC-MS), whereas high-pressure liquid chromatography mass spectrometry (HPLC-MS) was used for quinmerac. In all substrates linearity was evaluated using matrix-matched calibration samples at five concentration levels (50-1000ngL(-1) for water, 5-500g kg(-1) for soil and 2.5-500g kg(-1) for sunflower or oilseed rape plant). Correlation coefficient was higher than 0.992 for all pesticides in all substrates. Acceptable mean recovery values were obtained for all pesticides in water (65.4-108.8%), soil (70.0-110.0%) and plant (66.1-118.6%), with intra- and inter-day RSD% below 20%. LODs were in the range of 0.250-26.6ngL(-1) for water, 0.10-1.8g kg(-1) for soil and 0.15-2.0g kg(-1) for plants. The methods can be efficiently applied for field dissipation studies of the pesticides in energy crop cultivations.