24中英文双语高效压液相色谱外文文献翻译基于共价有机框架的磁性吸附剂的多环芳烃固相萃取及其HPLC.docx

1、24中英文双语高效压液相色谱外文文献翻译基于共价有机框架的磁性吸附剂的多环芳烃固相萃取及其HPLC此文档是毕业设计外文翻译成品（ 含英文原文+中文翻译），无需调整复杂的格式！下载之后直接可用，方便快捷！本文价格不贵,也就几十块钱！一辈子也就一次的事！外文标题：A covalent organic framework-based magnetic sorbent for solid phase extraction of polycyclic aromatic hydrocarbons, and and its hyphenation to HPLC for quantitation外文作者：R

2、ong Wang ,Zilin Chen文献出处:Microchimica Acta , 2017 (5751) :1-8(如觉得年份太老，可改为近2年，毕竟很多毕业生都这样做)英文4589单词， 24889字符(字符就是印刷符)，中文7792汉字。Abstract A novel covalent organic framework based mag- netic adsorbent was developed for magnetic solid phase ex- traction (MSPE) of polycyclic aromatic hydrocarbons (PAHs). C

3、ovalent organic framework-LZU1 (= Lan Zhou University-1) was covalently immobilized onto polyethyleneimine-functionalized magnetic nanoparticles (COF-LZU1PEIFe3O4), and the resulting material was characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The effec

4、ts of the pH value of sample solution, percentage of acetonitrile, ex- traction time and sampling volume on MSPE of six PAHs were investigated. The COF-LZU1PEIFe3O4 displays high extraction efficiency for the PAHs such as pyrene, benzoapyrene, fluoranthene, benzaanthracene, benzoafluorathene and dib

5、enza,hanthracene. Following desorption with acetonitrile, the PAHs were quantified by HPLC. The MSPE-HPLC method shows low limit of detec- tion (0.220 pg mL1), wide linear range and good reproduc- ibility (relative standard deviations 4.4% for intra-day and inter-day precision). The method was succe

6、ssfully applied to determine PAHs in environmental samples. Good recoveries were obtained, ranging from 90.9 to 107.8% for water samples and 85.1 to 105.0% for soil samples.Keywords Covalent organic framework . COF-LZU1 . Magnetic solid phase extraction . Environmental analysis . Trace analysis . HP

7、LCIntroductionCovalent organic frameworks (COFs) are a class of crystalline porous materials that consist of light elements (C, H, B, N, O etc.) and are connected through strong covalent bonds 17. These materials possess much fascinating properties including high specific surface area, excellent the

8、rmal stability, high porosity, and low density. With these unique properties, COFs have aroused intensive interest of scientists for the greatpotential application in diverse areas 2, 4, such as gas storage 810, gas adsorption 11, 12, photoelectricity 13, 14, ca- talysis 15, 16 and chromatographic s

9、eparation 1719. However, there are still few reports focusing on their perfor- mance in the field of sample pretreatment. Metalorganicframeworks (MOFs) are another novel class of porous mate- rials similar to COFs, which have shown to be promising materials as sorbents for sample preparation in many

10、 pioneer works 2024. As the analogues of MOFs, COFs should possess great application potential in sample preparation.Hydrazone covalent organic frameworks have been synthe- sized and applied to the solid-phase microextraction (SPME) of pyrethroids 25 and pesticides 26 in vegetables. Therefore, it is

11、 possible to develop the application of COFs as promising adsorbent in sample pretreatment.Since the first discovery of COF materials in 2005 1, a variety of COFs have been reported. Imine-linked COF-LZU1 (Lan Zhou University-1) was first designed and synthesized by Wang group in 2011 15, which was

12、constructed with 1,3,5-triformylbenzene and 1,4-diaminobenzene through Schiff base reaction. COF-LZU1 has a two-dimensional (2D) layered-sheet structure and possesses large number of benzene rings and imine groups. Unlike boron-containing COFs that linked by boroxine or boronate-ester groups, COF-LZ

13、U1 is highly stable in water and most organic sol- vents 15. Niu et al. explored its performance as the stationary phase of capillary electrochromatography for separating or- ganic molecules 19. The results indicated that COF-LZU1 can offer strong stacking interaction and hydrophobic effect with the

14、 analytes. This suggests that it may be an excellent enrichment media for compounds with abundant system.Sample preparation is a critical step prior to analysis, espe-cially when complex samples are present. Over the past few decades, many new sample pretreatment techniques with low solvent consumpt

15、ion and low sample handling have been de- veloped and applied to extract target compounds from different matrices 27, 28. Among these techniques, magnetic solid-phase extraction (MSPE) has attracted increasing atten- tion due to its large adsorption capacity and high extraction efficiency 29. Additi

16、onally, magnetic nanoparticles (MNPs) can be rapidly separated from sample matrix via an external magnet, which would simplify operation procedure and short- en analysis time. Considering of the features of COF-LZU1 and MSPE, we attempted to prepare a COF-LZU1 functionalized MNPs and apply to magnet

17、ic solid-phase extraction. In order to achieve the immobilization of COF-LZU1, polyethyleneimine-functionalized Fe3O4 nanoparticles (PEI Fe3O4) 30 were chosen as the magnetic support. With the numerous active amino groups in the structure of PEI, COF-LZU1 can be covalently bonded to the surface of P

18、EIFe3O4 through Schiff base reaction.Polycyclic aromatic hydrocarbons (PAHs) are well-known environment pollutants, which are considered to be carcino- genic and mutagenic to human beings. It is of great impor- tance to monitor and control the amount of PAHs in environment. Since the concentration o

19、f PAHs in environmental samples is usually in trace levels, it is necessary to enrich PAHs by efficient sample pretreatment method before instrumental analysis 3134. Considering the properties of COF-LZU1 and PAHs, COF-LZU1 based MSPE method was expected to exhibit high extraction efficiency and cap

20、acity for analysis of PAHs in environment. Herein, in this work, we reported the fabrication of a novel COF-LZU1 functionalized MNPs (COF- LZU1PEIFe3O4) and its application for the MSPE of PAHs. Fe3O4 nanoparticles were first coated with PEI, then COF-LZU1 was grown on the surface of MNPs attributin

21、g to the covalent bonding between the PEI layer and COF- LZU1. The morphology and surface properties of nanoparticles were characterized by transmission electron microscopy (TEM) and Fourier-transformed infrared spectroscopy (FT-IR). COF-LZU1PEIFe3O4 were used as magnetic adsorbent for extraction of

22、 PAHs from environmental samples. The extraction performance was systematically investigated. To the best of our knowledge, it is the first time that COF-LZU1 is immobilized on solid support for sample preparation.ExperimentalChemicals and materials1,3,5-Triformylbenzene, 1,4-diaminobenzene, pyrene

23、(PYR), benzoapyrene (BaPY), phenanthrene, anthracene, naph- thalene, 1-naphthol were purchased from SigmaAldrich (MO, USA, www.sigma-). Fluoranthene (FLU), benzaanthracene (BaAN), benzoafluorathene (BaFL), dibenza,hanthracene (Da,hAN) were obtained from TCI (Shanghai, China, ). 4-Phenylphenol, 4-vin

24、ylbiphenyl and 1,4-dioxane, polyethyleneimine (PEI, Mw 70,000 g mol1, 50% (w/v) aqueous solution) were bought from Aladdin Reagent (Shanghai, China, www. aladdin-). Methanol and acetonitrile were HPLC grade (Tedia, OH, USA, ). Other reagents were analytical grade. Purified water was obtained from a

25、Milli-Q system (MA, USA, US/en).InstrumentationThe chromatographic analysis was performed by a Shimadzu 20A HPLC system (Tokyo, Japan, . cn), which equipped with two 20A pumps, a six-port valve, a 20A UV detector, and a 10A fluorescent detector. The chromatographic separation was carried out by a C1

26、8 column (150 mm 4.6 mm i.d., 5 m particle size, GL Science, Tokyo, Japan, www.shimadzu-). The mobile phaseconsisted of methanol and water (89/11, v/v) and the flow rate was 1.0 ml min1. The detection wavelength of fluorescent detector was set at 290 nm (exiting wavelength) and 430 nm (emission wave

27、length), while the detection wavelength of UV detector was set at 254 nm. The column temperature for HPLC separation was set at 30 C.Fourier-transformed infrared spectroscopy (FT-IR) charac- terization was performed on Thermo Nexus 470 FT-IR system (MA, UAS, ). The transmission electron microscopy (

28、TEM) image was obtained by a JEM-2100 (HR) transmission electron microscope (TEM) (JEOL, Tokyo, Japan, https:/www.jeol.co.jp/en/).Preparation of COF-LZU1PEIFe3O4PEIFe3O4 was prepared following Amals method 30. Briefly, FeCl24H2O (0.7 g) was firstly dissolved in 80 mL of distilled water. Then 10 mL o

29、f KNO3 (2.0 M), 10 mL of NaOH (1.0 M) and PEI (1.7 g) were added to this solution sequentially under nitrogen atmosphere. After being stirred for 2 h at 90 C, the synthesized nanoparticles were collected by a magnet, followed by washing with water for several times.1,3,5-Triformylbenzene (3 mg), 1,4

30、-diaminobenzene(3 mg) were dissolved in 3 mL of 1,4-dioxane and followed by the addition of 60 L of 3 M aqueous acetic acid. PEI Fe3O4 (100 mg) were suspended in above solution with ultrasonication. For modification of COF-LZU1, the temper- ature was rose to 150 C and reacted for 24 h. Finally, the

31、COF-LZU1PEIFe3O4 were washed with ethanol thor- oughly and dried in the oven (60 C).COF-LZU1PEIFe3O4 based MSPE proceduresPAHs standard were dissolved in 20 mM phosphate buffer (pH 9, containing 1% acetonitrile, v/v) at certain concentra- tion. COF-LZU1PEIFe3O4 (5 mg) were carefully weighed and mixe

32、d with 20 mL of sample solution. The mix- ture was stirring for 30 min with the assistant of a magnetic stirring apparatus (two bottles containing the mixture and stir ring bar were placed together and stirring). Before collection of nanoparticles, the stirring bar was removed by a magnet under stirring. After that, the nanoparticles were separated from the solution by an extern