In this work, a rapid, highly selective, reusable and effective method was developed for simultaneous determination of alachlor, acetochlor and pretilachlor in eld soil by GC-MS coupled with MIL-101 based SPE. Main factors affecting the SPE by using MIL-101 were optimized. Moreover, by comparing with the other commercial materials such as C 18 , PSA and Florisil, the MIL-101(Cr) exhibited excellent adsorption performance, which aimed at amide herbicides. On the other hand, method validation displayed excellent method performance, achieving good linearities with r 2 ≥ 0.9921, limits of detection between 0.25-0.45 µg kg − 1 , enrichment factors ≥ 89, matrix effect in the range of ± 20%, recoveries between 86.3% and 102.4%, and RSD lower than 4.38%. The developed method was successfully applied to the determination of amide herbicides in soil taken from the wheat, corn and soybean eld at different depths, where the concentration of alachlor, acetochlor and pretilachlor were in the range of 0.62-8.04 µg kg − 1 . It was demonstrated that the more depth of soil, the lower of three amide herbicides. This nding could be proposed a novel method to detect the amide herbicides in the agriculture and food industry.

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In this paper, the peroxidaselike catalytic effect of gold nanoparticles (AuNPs) was explored in dye wastewater treatment by visible light excitation. Using hydrogen peroxide as a substrate, the peroxidaselike reaction was evaluated with AuNPs catalyzing the substrate oxidative degradation of the organic dye rhodamine B (RhB). The synthesized AuNPs were characterized by transmission electron microscopy. The degradation of RhB was observed by a UV-visible spectrophotometer. The results showed that under visible light irradiation, the AuNPs exhibited good peroxidaselike catalytic activity for the oxidative degradation of RhB by hydrogen peroxide. By studying the light wavelength and light intensity-dependent reaction rates, radical trapping, and hole acceptor incorporation, it was found that AuNPs can absorb photon energy and generate hot electrons through a localized surface plasmon resonance effect under light irradiation. Subsequently, hot electrons flow into the molecular orbitals of H2O2 based on energy matching, activating the molecule and transforming it into the transition state, which is proceeded by breakdown to release hydroxyl radicals (⋅OH) for oxidative destruction of RhB.

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