Showing papers on "Benzoylurea published in 2013"

Dispersive liquid-phase microextraction in combination with HPLC for the enrichment and rapid determination of benzoylurea pesticides in environmental water samples.

Abstract: Benzoylurea (BU) insecticides have contributed greatly to the output of crops. Their residue in the environment put serious threats on human health and environmental safety. In this study, we have established a new, rapid, and reliable method for the monitoring of typical BU insecticides such as diflubenzuron, flufenoxuron, triflumuron, and chlorfluazuron with dispersive liquid-liquid microextraction prior to HPLC. Chlorobenzene and ethanol were employed as the extraction solvent and disperser solvent, respectively. The possible parameters which would influence the extraction efficiency such as the kinds and volumes of extraction and disperser solvents, extraction time, sample pH, centrifuging time, and salting-out effect were optimized in detail. Under the optimal conditions, the linear range of proposed method was in the range of 1.0-70 μg/L. The detection limits varied from 0.24 to 0.82 μg/L and the precision of the method was <6.5% (RSD, n = 6). The proposed method was validated with real water samples and satisfactory spiked recoveries were achieved. All these results indicate that the proposed method is a low cost, easy to operate, efficient, and sensitive method for the analysis of BU insecticides in water samples.

Design, synthesis, and insecticidal evaluation of new benzoylureas containing amide and sulfonate groups based on the sulfonylurea receptor protein binding site for diflubenzuron and glibenclamide.

Abstract: On the basis of the sulfonylurea receptor (SUR) protein binding site for diflubenzuron and glibenclamide, 15 new benzoylphenylureas containing amide and sulfonate groups were designed and synthesized Their structures were characterized by (1)H nuclear magnetic resonance (NMR) and elemental analysis [or high-resolution mass spectrometry (HRMS)] The larvicidal activities of the new compounds against oriental armyworm and diamondback moth were evaluated Compound II-3 showed nearly the same level of insecticidal activity against oriental armyworm as commercial insecticide flucycloxuron and, thus, emerged as a new lead compound for the development of new benzoylurea insecticides

Multi-residue method development of 8 benzoylurea insecticides in mandarin and apple using high performance liquid chromatography and liquid chromatography-tandem mass spectrometry

Abstract: Multi-residue method of eight benzoylurea insecticdes (8BUs; diflubenzuron, triflumuron, hexaflumuron, teflubenzuron, novaluron, lufenuron, flufenoxuron, and chlorfluazuron) in apple and mandarin were developed with high performance liquid chromatography and liquid chromatography-tandem Mass spectrometry. Using multiresidue standard solutions, extraction, partition, and clean-up procedures have been established. Extraction with acetone and partition with n-hexane gave reasonable recovery of more than 90%. Clean-up with florisil-glass column using acetone/n-hexane as eluting solvents resulted in good efficiency of higher than 94%. By employing the established analytical method, recovery test of 8BUs in mandarin and apple was conducted to give recovery of 80–110%, which satisfies the Korea Food & Drug Administration criteria. The method limit of quantitation (MLOQ, 0.02 mg/kg) was lower than 1/2 of maximum residue limits of crops. Excellent sensitivity and selectivity were obtained with liquid chromatography tandem mass spectrometry (LC-MS/MS)-Electrospray ionization(-) even in the samples with no clean-up, suggesting LC-MS/MS can be used for the fast multi-residue method of 8 benzoylurea insecticides in mandarin and apple.

HPLC-DAD data coupled with second-order calibration method applied to food analysis: Simultaneous determination of six benzoylurea insecticides in various fruit samples by selecting time region of chromatogram

Abstract: This work presents a novel application of second-order calibration based on self-weighted alternating trilinear decomposition (SWATLD) algorithm for analyzing the HPLC-DAD data. The proposed method makes it possible to simultaneously determine teflubenzuron, hexaflumuron, flufenoxuron, chlorfluazuron, diflubenzuron and benzoylurea in different fruit samples, i.e. pear, apple and banana, in the selected time region of chromatogram. The concentration, elution time and spectral information of these benzoylurea insecticides are selectively extracted from complex matrices even in the presence of unknown interferences. The root-mean-square error of prediction (RMSEP) and figures of merit, including sensitivity (SEN), selectivity (SEL) and limit of detection (LOD) are employed to access the performance of the method. The LODs obtained for these insecticides are within the range 0.017-0.26 ppm in pears, 0.039-0.33 ppm in apples, 0.041-0.44 ppm in bananas, respectively. Such a chemometrics-based protocol holds great potential to be extended as a promising alternative for more practical applications in food safety and quality monitoring.

Pesticide composition with flufiprole and benzoylurea insecticide

Abstract: The invention discloses a pesticide composition with flufiprole and benzoylurea insecticide. The effective components are flufiprole and benzoylurea insecticide, the benzoylurea insecticide is one of chlorbenzuron, hexaflumuron and chlorfluazuron, the weight ratio of the flufiprole to benzoylurea insecticide is (1:20)-(20:1), the weight percentage of the weight summation of the flufiprole and the benzoylurea insecticide in the composition is 2-80%. The pesticide composition disclosed by the invention is used for preventing and controlling vegetable plutella xylostella. The preventing and controlling effect of the pesticide composition is obviously improved in comparison with that of a single agent, the use dosage of the pesticide is lowered, the influence on the environment caused by the pesticide is reduced, and the drug use cost is lowered.

Synthesis of Imides and Benzoylureas by Direct Oxidation of N-methylenes of Amides and Benzylureas:

Abstract: Some amides and benzylureas can be oxidised to imides and benzoylureas, respectively, using silver(I) nitrate (20 mol %), copper(II) sulfate pentahydrate (20 mol %), ammonium persulfate (3.0 equiv....

Pesticidal compositions comprising benzoylurea compound and further pesticidal compound and their uses

Abstract: The present invention relates to Pesticidal compositions comprising a benzoylurea compound (I) being flufenoxuron or teflubenzuron and further pesticidal compounds (II) and optionally compounds (III) in synergistically effective amounts. The invention also relates to the use of said compositions for controlling, combating invertebrate pests. The invention further relates to methods of applying such compositions.

Insecticidal composition containing oxymatrine and benzoylurea components

Abstract: The invention relates to an insecticidal composition containing oxymatrine and benzoylurea components. The mass ratio of the oxymatrine to benzoylurea insecticides is (1-40): (40-1). The benzoylurea insecticides are one or more of hexaflumuron, flufenoxuron, chlorfluazuron, lufenuron, novaluron, chlorbenzuron, diflubenzuron and teflubenzuron. The insecticidal composition can be used for preventing beet armyworms, rice leaf folders, cotton bollworms, plutella xylostellas, cabbage caterpillars, prodenia litura, apple skin worms, whiteflies and red spider mites.

Manufacturing method and composition in effervescent tablets of mosquito larvacide

Abstract: PURPOSE: An insecticide of an effervescent tablet type for controlling mosquito larvae is provided to prevent an effect to aquatic organisms using a submaterial used in manufacturing pharmaceutical products. CONSTITUTION: Water soluble main ingredient powder of high concentration contains organophosphorus compounds, benzoylphenylurea-based compounds, benzoylurea-based compounds, natural insecticidal compounds including novaluron, diflubenzuron, chlorfluazuron, teflubenzuron, flufenoxuron, and temephos, and phyrethrum. An effervescent tablet is prepared using sodium hydrogen carbonate, sodium carbonate, citric acid, adipic acid, lactose, hydroxypropyl cellulose, talc, magnesium stearate, and microcrystalline cellulose.