QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation methods were developed to help monitor pesticides in a range of food samples [1]. These methods are quite labor intensive, however, since they include several manual steps, such as shaking, centrifugation, and dispersive SPE. If dispersive SPE clean up of QuEChERS type extracts could be automated, laboratory productivity for monitoring pesticide residues in food could be improved significantly. In the work presented here, an automated dispersive SPE clean-up method for QuEChERS extracts was developed and combined with LC/MS/MS analysis of the cleaned extracts. Extracts were prepared with commercially available kits from Agilent Technologies. Automation was achieved using a GERSTEL MPS XL PrepStation configured with an Anatune CF-100 centrifuge. Analytical methodology for confirming the presence of a variety of pesticides in a range food samples was developed using an Agilent G6460A Triple Quadrupole Mass Spectrometer. The sensitivity and selectivity of LC/MS/MS enable sufficiently low limits of determination to meet acceptance criteria for reporting the maximum residue levels (MRLs) that are established by regulatory agencies.
The ability to automate the dispersive SPE clean-up of QuEChERS extracts combined with introduction of the cleaned extract directly to the LC/MS/MS system results in improved laboratory productivity by streamlining the complete analytical process.
