RESUMEN
The metal-organic framework (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] was tested for extraction of pyrimicarb, procymidone, malathion, methyl parathion and α- and ß-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 (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(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 µg/mL), with correlation coefficients ranging from 0.9990 to 0.9997. Comparison between (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] and conventional sorbent (silica gel) showed better performance of the (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] polymeric sorbent for all pesticides tested.