Reliable analysis of chlorophenoxy herbicides in soil and water by magnetic solid phase extraction and liquid chromatography

There is no previous work on the determination of chlorophenoxy acid herbicides in soils. Here we analysed six chlorophenoxy acid herbicides using magnetic solid phase extraction for their preconcentration, then liquid chromatography and tandem mass spectrometry with a triple-quadrupole (LC-QqQ-MS/MS) in the multiple reaction monitoring mode. 40 mg of CoFe2O4@polypyrrole magnetic nanoparticles was added to a 30-mL sample, and vortex stirring was applied for 10 min. Analytes were desorbed using acidified methanol. The reliability of the results was validated through recovery assays, giving mean values in the 80–117 range. The intraday precision was in the 6.3–14% range, in terms of relative standard deviation.