Evaluation of membrane filtration for cleanup in multi-residue pesticide analysis of spinach

- Enhanced cleanup method involving membrane filtration for pesticide analysis.
- The cleanup characteristics are changed by types of membranes and elute mixtures.
- Membrane filtration methods shows better cleanup than the conventional method.

This study reports a new membrane filtration-based cleanup method for the analysis of pesticides. Recovery and cleanup by membrane filtration using 11 different membranes, classified by their molecular weight cut-off, pore size, and material, were examined. Three different eluent mixtures were also examined. The results indicated that membranes with a 0.1-μm pore size were the most effective among those tested. In particular, hydrophobic polyvinylidene difluoride and hydrophobic polytetrafluoroethylene gave better recoveries and cleanup than other membranes. Results from GC chromatograms and matrix effects showed that membrane filtration afforded better cleanup than the modified QuEChERS method. Furthermore, over 90% of the 89 pesticides tested had acceptable recoveries using these two membranes, according to an acceptable recovery range of 70-120%. Therefore, this technique has potential as an effective cleanup method.