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The metal-organic framework [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ was synthetized and characterized by X-ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid-phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0-1000.0 μg/kg for procymidone and 200.0-1000.0 μg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 μg/kg fortification levels, and resulted in recoveries in the range of 52.7-135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 μg/kg and from 50.0 to 200.0 μg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.

We report the synthesis, characterization, and application of [Zn(1,4-benzenedicarboxylate)(H2O)2]n, Zn(1,4-benzenedicarboxylate)0.99(NH2-1,4-benzenedicarboxylate)0.01(H2O)2]n, [Zn(1,4-benzenedicarboxylate)0.95(NH2-1,4-benzenedicarboxylate)0.05(H2O)2]n and [Zn(1,4-benzenedicarboxylate)0.9(NH2-1,4-benzenedicarboxylate)0.1(H2O)2]n as sorbents for the extraction of multiclass pesticides from coconut palm. Liquid chromatography with ultraviolet diode array detection was used as the analysis technique, and the experiments were performed at one fortification level (0.1 μg g−1). The recoveries were 47–67, 51–70, 58–72 and 64–76% for [Zn(1,4-benzenedicarboxylate)(H2O)2]n, Zn(1,4-benzenedicarboxylate)0.99(NH2-1,4-benzenedicarboxylate)0.01(H2O)2]n, [Zn(1,4-benzenedicarboxylate)0.95(NH2-1,4-benzenedicarboxylate)0.05(H2O)2]n, and [Zn(1,4-benzenedicarboxylate)0.9(NH2-1,4-benzenedicarboxylate)0.1(H2O)2]n, respectively, with relative standard deviation ranging from 1 to 7% (n = 3). Detection and quantification limits were 0.01–0.05 and 0.05–0.2 μg g−1, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.01–10.0 μg g−1) with r2 > 0.9991. A direct comparison of [Zn(1,4-benzenedicarboxylate)0.9(NH2-1,4-benzenedicarboxylate)0.1(H2O)2]n with the commercially available neutral alumina showed that [Zn(1,4-benzenedicarboxylate)0.9(NH2-1,4-benzenedicarboxylate)0.1(H2O)2]n was a similar extracting phase for the pesticides investigated. This article is protected by copyright. All rights reserved

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 β-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.