Showing papers on "Benzoylurea published in 2020"

Magnetic 3D hierarchical Ni/NiO@C nanorods derived from metal-organic frameworks for extraction of benzoylurea insecticides prior to HPLC-UV analysis

Abstract: Magnetic hierarchical nickel/nickel oxide/carbon nanorods (Ni/NiO@C) were prepared via the pyrolysis of a metal-organic framework containing nickel(II) nickel (Ni-MOF; Ni3(BTC)2) under argon atmosphere. In this material, magnetic Ni/NiO@C nanoparticles are embedded in porous carbon nanorods, and the morphology is similar to that of the original Ni-MOF precursor. The synthesized nanorods were applied as magnetic sorbents in the solid-phase extraction of five benzoylurea insecticides (flufenoxuron, chlorbenzuron, teflubenzuron, diflubenzuron and triflumuron), and their performance was evaluated under optimized conditions. The results show that the material exhibits high extraction recoveries from spiked samples (82.9%–107.6%) and linear response in the range of 0.2–450 μg·L−1. It is also characterized by relatively low limits of detection (50–100 ng·mL−1) at a signal-to-noise ratio of 3. The sorbent is chemically stable and can be repeatedly recycled, with little decline in extraction capacity after 20 cycles of reuse. The method was successfully applied to the quantification of benzoylureas in tea, wolfberry, millet, and oat samples, and it showed high extraction efficiency.

Dissolvable Mg/Al layered double hydroxides and surfactant as an extractant for trace analysis of benzoylurea insecticides by high performance liquid chromatography.

Abstract: A rapid and simple preconcentration method using dissolvable Mg/Al layered-double hydroxides (LDHs) and high performance liquid chromatography-photodiode array detection (HPLC-PDA) was developed for the analysis of benzoylurea insecticides (BUs) in water and honey samples. The proposed dissolvable LDHs for the extraction can be prepared in one step by the sequential addition of sodium hydroxide, magnesium chloride, aluminium chloride, and sodium dodecyl sulfate into the sample solution containing the target BUs. The co-precipitate phase was simply obtained after centrifugation, and the phase was then dissolved with formic acid before analysis by HPLC. The developed method provided an enrichment factor of 12.5-23.7. LODs were obtained in the range of 0.1-0.3 μg L-1 for deionized water, 0.2-2.0 μg L-1 for environmental waters, and 0.5-2.0 μg L-1 for the analyzed honey samples. Good recoveries ranging from 78.4 to 117.8% and 72.7 to 117.9% for water and honey samples, respectively, were obtained.

Deep eutectic solvent-based QuEChERS method combined with dispersive liquid–liquid microextraction for extraction of benzoylurea insecticides in cabbage leaves samples

Abstract: A microwave-assisted quick-easy-cheap-effective-rugged-safe method based on deep eutectic solvent was combined with lighter than water organic solvent-based-dispersive liquid–liquid microextraction...