Benzoylurea Insecticides In Water Samples Research Articles

Polyamidoamine dendrimer-functionalized silica nanocomposite with polydopamine coating for dispersive micro solid-phase extraction of benzoylurea insecticides in water samples

近年来,由农药残留导致的环境污染问题已引起社会的广泛关注,开发便捷高效的分析方法对农药残留进行检测和监测十分必要。研究设计并成功制备了聚多巴胺涂敷的聚酰胺-胺树状分子功能化的二氧化硅复合材料(SiO2-PAMAM-PDA),并采用透射电镜对其进行表征。开发了以此复合材料为吸附剂的分散微固相萃取方法(D-μ-SPE),并结合高效液相色谱对水基质中的4种苯甲酰脲类杀虫剂(BUs)残留进行了富集检测。多巴胺结构中含有丰富的苯环、氨基及羟基,可与目标物形成氢键、π-π相互作用,从而增强了材料对苯甲酰脲的萃取能力。对吸附剂用量、萃取时间等可能影响萃取效率的条件进行了单因素优化。在最优条件下,该方法的线性范围在10~500 μg/L之间,根据3倍信噪比(S/N)计算所得的检出限(LOD)为1.1~2.1 μg/L,回收率为82.8%~94.1%,相对标准偏差(RSD)为2.1%~8.0%。将建立的方法与已报道的以苯甲酰脲作为目标物的方法进行了对比,发现方法样品用量及萃取剂用量均较少,且所需前处理时间较短,有机溶剂消耗也较少,为苯甲酰脲类农药的检测提供了更快速、绿色的选择。为评估所开发方法的实际样品适用性,将其应用于3种河水样品中4种苯甲酰脲类杀虫剂的分析检测,所得回收率及RSD分别为69.5%~99.4%和0.2%~9.5%,表明此方法在实际样品中同样具有较高的准确性和精密度。

Dispersive micro-solid-phase extraction of benzoylurea insecticides in water samples with hyperbranched polyester composite as sorbent

Hyperbranched polyester was used as efficient and accessible sorbent in the dispersive micro-solid-phase extraction method.

In situ solvent formation microextraction combined with magnetic dispersive micro-solid-phase extraction for the determination of benzoylurea insecticides in water samples.

A simple, fast, effective, and environmentally friendly method, in situ solvent formation microextraction combined with magnetic dispersive micro-solid-phase extraction for the determination of four benzoylurea insecticides is presented herein for the first time. In the proposed method, 1-hexyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide was formed by the reaction between 1-hexyl-3-methylimidazolium chloride and lithium bis[(trifluoromethane)sulfonyl]imide and was used to extract benzoylurea insecticides. Then magnetic nanoparticles were added as carrier to retrieve and separate the ionic liquid from the sample solution. After the supernatant was removed, the ionic liquid was desorbed using acetonitrile and subsequently injected directly into a high-performance liquid chromatograph equipped with a variable wavelength detector for analysis. The main factors affecting the extraction efficiency were investigated by a one factor at a time approach. Under optimized conditions, the proposed method showed good repeatability (RSD = 2.2-4.5%) and linearity (2-300 μg/L), with correlation coefficients greater than 0.9994 and low limits of detection (0.67-1.46 μg/L). Finally, the method was successfully applied to the analysis of four benzoylurea insecticides in environmental water samples with good recoveries (73.2-85.8%).

Effervescence-assisted dispersive liquid–liquid microextraction based on the solidification of a floating ionic liquid with a special collection method for the rapid determination of benzoylurea insecticides in water samples

Dispersion liquid–liquid microextraction based on the solidification of a floating ionic liquid.

Analysis of benzoylurea insecticides in water samples with TiO2nanotube array micro-solid phase extraction coupled to high performance liquid chromatography

A rapid, easy to operate, and sensitive method was developed for the trace determination of benzoylurea insecticides based on a micro-solid phase extraction with highly ordered TiO2 nanotube arrays as the adsorbent prior to high performance liquid chromatography. The experimental results indicated that a good linear relationship was achieved between the peak areas and the concentrations of benzoylurea insecticides in the range of 0.1–40 μg L−1. The limits of detection (LODs) of diflubenzuron, chlorbenzuron, triflumuron and chlorfluazuron were 0.082, 0.026, 0.049 and 0.076 μg L−1, respectively. The proposed method was successfully used to determine the benzoylurea insecticides in environmental water samples. The spiked recoveries in the range of 76.5–102.4% were achieved. All these results demonstrated that the proposed method was of great value and would have great potential in the enrichment and determination of trace pollutants in the future.

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

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.