Badawy Mohamed E I, El-Nouby Mahmoud A M, Marei Abd El-Salam M
Department of Pesticide Chemistry and Technology, Faculty of Agriculture, Alexandria University, El-Shatby, Alexandria 21545, Egypt.
Int J Anal Chem. 2018 Oct 2;2018:3640691. doi: 10.1155/2018/3640691. eCollection 2018.
The present study aims to prepare two new types of chitosan-metal oxide nanoparticles (Ch-MO NPs), namely, chitosan-copper oxide nanoparticles (Ch-CuO NPs) and chitosan-zinc oxide nanoparticles (Ch-ZnO NPs), using sol-gel precipitation mechanism, and test them new as adsorbent materials for extraction and clean-up of different pesticides from water. The design of core-shell was implemented by metal oxide core with chitosan as a hard shell after crosslinking mechanism by glutaraldehyde and then epichlorohydrin. The characterizations of the prepared nanoparticles were investigated using Fourier transform infrared spectrometry (FT-IR), zeta potential, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). FT-IR confirmed the interaction between chitosan, metal oxide, and crosslinking mechanism. SEM and TEM explained that the nanoparticles have a spherical morphology and nanosize of 93.74 and 97.95 nm for Ch-CuO NPs and Ch-ZnO NPs, respectively. Factorial experimental design was applied to study the effect of pH, concentration of pesticide, agitation time, and temperature on the efficiency of adsorption of pesticides from water samples. The results indicated that optimum conditions were pH of 7, temperature of 25°C, and agitation time of 25 min. The SPE cartridges were then packed with Ch-MO NPs, and seven pesticides of abamectin, diazinon, fenamiphos, imidacloprid, lambda-cyhalothrin, methomyl, and thiophanate-methyl were extracted from water samples and determined by HPLC. The extraction efficiency of Ch-ZnO NPs was higher than Ch-CuO NPs, but both removed a larger amount of most of tested pesticides than the standard ODS cartridge (C18). The results showed that this method achieves rapid and simple extraction in small quantities of adsorbents (Ch-MO NPs) and solvents. In addition, the method is highly sensitive to pesticides and has a high recovery rate.
本研究旨在利用溶胶-凝胶沉淀机制制备两种新型壳聚糖-金属氧化物纳米颗粒（Ch-MO NPs），即壳聚糖-氧化铜纳米颗粒（Ch-CuO NPs）和壳聚糖-氧化锌纳米颗粒（Ch-ZnO NPs），并将它们作为新型吸附材料用于从水中萃取和净化不同农药。通过戊二醛然后环氧氯丙烷交联机制，以金属氧化物为核、壳聚糖为硬壳实现核壳结构设计。使用傅里叶变换红外光谱（FT-IR）、zeta电位、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和X射线衍射（XRD）对制备的纳米颗粒进行表征。FT-IR证实了壳聚糖、金属氧化物和交联机制之间的相互作用。SEM和TEM表明，纳米颗粒呈球形，Ch-CuO NPs和Ch-ZnO NPs的纳米尺寸分别为93.74和97.95nm。采用析因实验设计研究pH、农药浓度、搅拌时间和温度对水样中农药吸附效率的影响。结果表明，最佳条件为pH 7、温度25°C和搅拌时间25分钟。然后将Ch-MO NPs填充到固相萃取（SPE）小柱中，从水样中萃取阿维菌素、二嗪农、苯线磷、吡虫啉、高效氯氟氰菊酯、灭多威和甲基硫菌灵七种农药，并通过高效液相色谱（HPLC）进行测定。Ch-ZnO NPs的萃取效率高于Ch-CuO NPs，但两者去除的大多数被测农药量均比标准ODS小柱（C18）多。结果表明，该方法在少量吸附剂（Ch-MO NPs）和溶剂中实现了快速、简单的萃取。此外，该方法对农药高度敏感，回收率高。
