Optimization and establishment of QuEChERS based method for determination of propoxycarbazone and its metabolite in food commodities by liquid chromatography coupled to tandem mass spectrometry

This study reports a method for propoxycarbazone pesticide determination including its metabolite in food commodities (lettuce, beetroot, soybean meal and honey). Both compounds were extracted, and samples cleaned using a buffered QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method based on the AOAC Official Method, followed by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Both matrix-matched calibration curves showed good linearity (R2 = 0.99) within the tested ranges. Method performance was assessed on the basis of recovery and intra/inter-day precision studies at spiked concentrations of 10 (25) and 50 µg/kg (n = 5). Mean recovery rates were between 73 and 110%, while precision studies, assessed by relative standard deviation (RSD), were ≤20%. The limits of quantification (LOQ) were established as 10 or 25 µg/kg, depending on the matrix, which are low enough for monitoring residues at regulated maximum residue levels.