Surface Modification Of Nanoscale Zerovalent Iron Particles And Their Applications In Enrichment And Determination Of Typical Environmental Pollutants

Safarikova and Safarik first proposed magnetic solid phase extraction?MSPE?in1999,and introduced it into environmental sample pre-treatment field.As a new mode of SPE.Magnetic solid phase extraction has merits such as simplicity,rapidness,high enrichment factor,short extraction time and low consumption of organic solvents.Nanoscale zero-valent iron?NZVI?has been widely used in environmental engineering field due to its high reactivity,large specific surface area,and abundant reactive sites,but there are very few reports on its applications in environmental analytical chemistry due to the fact that bare NZVI particles are easily oxided and agglomerated.Functional modification is a good way to enhance the various applicabilities for various pollutants and dispersities,and which make NZVI have great application prospect in the field of environmental analytical chemistry.In this paper,NZVI particles are modified with several functional materials.The new synthesized magnetic nanoparticles are investigated as the magnetic solid phase extraction adsorbents for preconcentration and determination of typical environmental pollutants prior to high performance liquid chromatography coupled with variable wavelength detection.The main contents are as follows:?1?Fe@MgAl-LDH magnetic nanoparticles were synthesized and characterized with TEM,XRD techniques,which was investigated to develop a novel method for proconcentration and determination of bisphenol A,4-octylphenol and 4-nonylphenol from environmental water samples.Under the optimal conditions,linear ranges were obtained in the range of 0.5-200?g·L^-1,the detection limits were in the range of0.24-0.34?g·L^-1,and the spiked recoveries were achieved in the range of 96.0-99.3%.?2?Fe@MOF-5 magnetic nanoparticles were prepared and characterized with TEM,EDS,XRD techniques.This new magnetic material was used as the adsorbent to develop a new method for enrichmment and determination of carbazole,9-methylcarbazole,dibenzothiophene,4-methyldibenzothiopheneand4,6-dimethyldibenzothiophene from environmental water samples.Under the optimal conditions,there were good linearship between the concentration and the peak area in the range of 0.05-200?g·L^-1,the detection limits were in the range of 0.025-0.033?g·L^-1.Real water samples were used to validate the applicability of the proposed method,the spiked recoveries were in the range of 92.6-97.3%.?3?Fe@MIL-101?Cr?magnetic nanoparticles were prepared and characterized with TEM,EDS,XRD techniques,which was used to establish a magnetic solid phase method for proconcentration and determination of naphthalene,anthracene,fluoranthene and pyrene from environmental water samples.Under the optimal conditions,linear ranges were achieved in the range of 0.1-500?g·L^-1,the detection limits were in the range of 0.044-0.064?g·L^-1,and the spiked recoveries were in the range of 85.7-97.3%.?4?Fe@Ag@DMB magnetic nanoparticles were synthesized and characterized with TEM,EDS techniques.This new material was used to develop a novel method for simultaneous proconcentration and determination of Pb?II?,Cd?II?and Hg?II?ions from environmental water samples.Under the optimal conditions,linear ranges were in the range of 0.05-200?g·L^-1,the detection limits were in the range of 0.011-0.031?g·L^-1,and the spiked recoveries were in the range of 97.5-103.2%.?5?Magnetic and thermos dual-responsive Fe@SiO₂@p?NIPAM-co-DMMA?nanoparticles were prepared and characterized with TEM,XRD techniques,which was used as the adsorbent for developing a novel method for proconcentration and determination of four Sudan Red dyes from environmental water samples.Under the optimal conditions,linear ranges were obtained in the range of 0.05-500?g·L^-1,the detection limits were in the range of 0.005-0.013?g·L^-1,and the spiked recoveries were in the range of 97.4-102.6%.