A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex ...A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex Havil(UR)were chosen to show the advantage of this method.The sample enrichment and separation were展开更多
In this study,graphene oxide was covalently immobilized on silica-coated magnetite and then modified with 2-phenylethylamine to give a nanocomposite of type Fe3O4@SiO2@GO-PEA that can be applied to the magnetic solid-...In this study,graphene oxide was covalently immobilized on silica-coated magnetite and then modified with 2-phenylethylamine to give a nanocomposite of type Fe3O4@SiO2@GO-PEA that can be applied to the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons（PAHs） from water samples.The resulting microspheres（Fe3O4@SiO2@GO-PEA） were characterized by Fourier transform-infrared spectroscopy（FT-IR）,scanning electron microscopy（SEM）,CHNS elemental analysis,and vibrating sample magnetometry（VSM） techniques.The adsorbent possesses the magnetic properties of Fe3O4 nanoparticles that allow them easily to be separated by an external magnetic field.They also have the high specific surface area of graphene oxide which improves adsorption capacity.Desorption conditions,extraction time,amount of adsorbent,salt concentration,and pH were investigated and optimized.Following desorption,the PAHs were quantified by gas chromatography with flame ionization detection（GC-FID）.The limits of detection（at an S/N ratio of 3） were achieved from 0.005 to0.1 μg/L with regression coefficients（R2） higher than 0.9954.The relative standard deviations（RSDs） were below 5.8%（intraday） and 6.2%（inter-day）,respectively.The method was successfully applied to the analysis of PAHs in environmental water samples where it showed recoveries in the range between 71.7%and 106.7%（with RSDs of 1.6%to 8.4%,for n = 3）.The results indicated that the Fe3O4@SiO2@GO-PEA microspheres had a great promise to extraction of PAHs from different water samples.展开更多
基金supported by the National Science and Technology Major Project for Major Drug Development(No.2013ZX09508104)the Traditional Chinese Medicine Industry Research Special Project(No.201307002)the National Science&Technology Major Project Key New Drug Creation and Manufacturing program(No.2011ZX09307002-03)of the People's Republic of China
文摘A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex Havil(UR)were chosen to show the advantage of this method.The sample enrichment and separation were
文摘In this study,graphene oxide was covalently immobilized on silica-coated magnetite and then modified with 2-phenylethylamine to give a nanocomposite of type Fe3O4@SiO2@GO-PEA that can be applied to the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons（PAHs） from water samples.The resulting microspheres（Fe3O4@SiO2@GO-PEA） were characterized by Fourier transform-infrared spectroscopy（FT-IR）,scanning electron microscopy（SEM）,CHNS elemental analysis,and vibrating sample magnetometry（VSM） techniques.The adsorbent possesses the magnetic properties of Fe3O4 nanoparticles that allow them easily to be separated by an external magnetic field.They also have the high specific surface area of graphene oxide which improves adsorption capacity.Desorption conditions,extraction time,amount of adsorbent,salt concentration,and pH were investigated and optimized.Following desorption,the PAHs were quantified by gas chromatography with flame ionization detection（GC-FID）.The limits of detection（at an S/N ratio of 3） were achieved from 0.005 to0.1 μg/L with regression coefficients（R2） higher than 0.9954.The relative standard deviations（RSDs） were below 5.8%（intraday） and 6.2%（inter-day）,respectively.The method was successfully applied to the analysis of PAHs in environmental water samples where it showed recoveries in the range between 71.7%and 106.7%（with RSDs of 1.6%to 8.4%,for n = 3）.The results indicated that the Fe3O4@SiO2@GO-PEA microspheres had a great promise to extraction of PAHs from different water samples.
