Potential of a metal-organic framework as a new material for solid-phase extraction of pesticides from lettuce (Lactuca sativa), with analysis by gas chromatography-mass spectrometry

The metal-organic framework (infinity)[(La0.9Eu0.1)(2)(DPA)(3)(H2O)(3)] was tested for extraction of pyrimicarb, procymidone, malathion, methyl parathion and alpha-and beta-endosulfan from lettuce, with analysis using GC/MS in SIM mode. Experiments were carried out in triplicate at two fortification levels (0.1 and 0.5 mg/kg), and resulted in recoveries in the range of 78-107%, with RSD values between 1.6 and 8.0% for (infinity)[(La0.9Eu0.1)(2)(DPA)(3) (H2O)(3)] sorbent. Detection and quantification limits ranged from 0.02 to 0.05 mg/kg and from 0.05 to 0.10 mg/kg, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.05-10.0 mu g/mL), with correlation coefficients ranging from 0.9990 to 0.9997. Comparison between (infinity)[(La0.9Eu0.1)(2)(DPA)(3)(H2O)(3)] and conventional sorbent (silica gel) showed better performance of the (infinity)[(La0.9Eu0.1)(2)(DPA)(3)(H2O)(3)] polymeric sorbent for all pesticides tested.