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چکیده
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A novel high-efficiency, reusable nanocatalyst functionalized with DABCO charge was successfully fabricated on magnetic silica. This catalyst was identified by XRD, TGA, VSM, FE-SEM, EDX, and FT-IR analyses. Fe3O4@SiO2@Mel@DABCO as a recoverable catalyst for 2- amino-4H-chromenes synthesis. Among the points that lead to the superiority of this catalyst, we can mention the use of green solvent, products with high yield (84-98%) in a short period, suitable temperature conditions, and simple collection of the reaction medium and its ability. In addition, the effectiveness of the synthesized magnetic sorbent in the microextraction method was examined. Due to the magnetic nature of the sorbents, the magnetic solid phase extraction (MSPE) was selected. Fipronil and promethrin were chosen as purpose model analytes and detected by HPLC-UV device. The results showed the LDRs in the range of 0.5-500 μg L-1 (determination coefficient higher than 0.9969). The LODs of the method were calculated to be between 0.11-0.13 μg L-1. The limits of quantification (LOQs) of the technique were also estimated to be in the range of 0.37-0.42 μg L-1. To verify the correctness of the proposed method, the relative standard deviation (RSDs%) inter-day was 2.9% and inter-day was 4.1%. The enrichment factors for fipronil and prometryn were 53 and 61, respectively. Moreover, the absolute recovery was in the range of 60-69%. The batch to batch RSD was also in the range of 3.9-4.3%. The method was successfully used to extract and determine selected pesticides in samples of tomato, cucumber, wastewater, and pear.
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