Analytical Methods
·
2015
·Vol. 8
·期 4
·919-924
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IF 1.821
Bing Yu,Hailin Cong,Lei Xue,Chao Tian,Xiaodan Xu,Qiaohong Peng,Shujing Yang
Monodisperse silica microspheres with average diameters from 1 μm to 2 μm were synthesized by a modified Stöber method, in which an ethanolic solution of tetraethyl orthosilicate (TEOS) was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol and ammonia. The effects of reactant amounts, supply rate, and reaction temperature on the microsphere morphology were investigated. After surface modification with octadecyl trichlorosilane, the obtained monodisperse C18-silica microspheres with an average diameter of 1.5 μm were applied to ultra performance liquid chromatography (UPLC) separation of fullerenes. Because of having a smaller size, the 1.5 μm monodisperse C18-silica UPLC stationary phase shows ultra high efficiency compared with the commercial C18-silica HPLC stationary phase with average diameters from 5 to 50 μm.
研究领域:
材料科学
·
分析化学
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DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2022
·Vol. 414
·期 17
·4897-4907
·
IF 4.478
Yang Zhenglun,Chen Yihui,Jia Jianggang,Hou Chunyan,Xuan Rongrong,Wang Tingting
In the current study, the C18-modified halloysite was fabricated via silylation reaction and subsequently used as sorbent in matrix solid-phase dispersion (MSPD) for the extraction of bisphenol A and diethylstilbestrol from human placenta, followed by high-performance liquid chromatography-tandem mass spectrometry analysis. The as-prepared sorbent was characterized by scanning electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, and thermo-gravimetric analysis. Varied parameters such as methanol concentration in wash solvent, pH and salt concentration in elution solvent, elution volume, and mass ratio of sample to sorbent were optimized. The adsorption capacities of bisphenol A and diethylstilbestrol on the developed C18-modified halloysite were 6.3 and 14.2 mg g −1 , respectively, higher than those on the commercial C18 silica gel. Under the optimal condition, the average recoveries of bisphenol A and diethylstilbestrol by MSPD varied from 91.0 to 106.0%, and the relative standard deviations were less than 10.6% for human placenta samples. The limits of detection in the human placenta were 0.2 μg kg −1 for bisphenol A and diethylstilbestrol. The simple C18-modified halloysite-based MSPD method holds great potential for the determination of trace bisphenol A and diethylstilbestrol in the human placenta and other tissues of pregnant women with high sensitivity, accuracy, and reliability. Graphical abstract
研究领域:
分析化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2012
·
IF 3.794
Keyi Wang,Yingzhuang Chen,Huihui Yang,Yi Li,Lihua Nie,Shouzhuo Yao
An n-octadecanethiol (C 18 )/3-mercapto-1-propane-sulfonate (MPS) modified organic–inorganic hybrid silica monolithic column possessing vinyl ligands through thiol-ene click chemistry for capillary electrochromatography (CEC) is described. The proposed column is prepared via the sol–gel process by in situ co-condensation using vinyltrimethoxysilane (VTMS) and tetra-methoxysilane (TMOS) as precursors. Examination by SEM shows that the capillary has homogenous macroporous morphology and is well attached to the inner wall of the capillary. The obtained C 18 -MPS-VTMS silica hybrid monolithic column demonstrated an enhanced hydrophilic property and could be applied as a reversed-phase stationary phase in CEC directly. Compared with unmodified VTMS silica hybrid monolithic column, stronger EOF was observed using this monolithic column. VTMS/TOMS ratios in the reaction mixture were varied and 1:3 was found to be optimum. Good separations of benzenes, aromatic amines, acids and peptides were achieved, the lowest plate height of ∼3 μm was obtained, the peak symmetry range from 0.98 to 1.29. The resulting C 18 -MPS-VTMS silica hybrid monolithic column can be used in different separation modes, including reversed phase mode and ion exchange mode.
研究领域:
分析化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 3
·855-862
·
IF 3.719
Yan Fufeng,Zhang Yuanchang,Zhang Shuai,Zhao Jihong,Liu Shunli,He Linghao,Feng Xiaozhong,Zhang Hongzhong,Zhang Zhihong
We report on an efficient method for the production carboxy-modified graphene (carboxy-GR), and its application to a highly sensitive immunoassay for the livestock feed additive clenbuterol. Octadecanoic acid is shown to self-assemble on carboxy-GR via intermolecular interaction. Goat anti-mouse IgG was conjugated to 1-octadecanethiol-modified carboxy-GR and then deposited by self-assembly on a C18-modified gold surface. The resulting sensor surface was used to quantify clenbuterol by both surface plasmon resonance and electrochemical impedance spectroscopy. The assay works in the 0.01 ng∙mL −1 to 10 ng∙mL −1 concentration range and the lower detection limit is 6.57 pg∙mL −1 . It is concluded that this fairly simple method can be extended to immunoassays for other food additives.
Principle of sensor system and immunoassay. (i) Binding of ACG–IgG with the alkyl chain of 1-octadecanethiol through intermolecular force onto the gold substrate; (ii) absorbance of Ab CLB onto the surface of ACG-IgG; and (iii) detection of CLB using an immunoassay based on Ab CLB –ACG–IgG.
研究领域:
材料科学
·
分析化学
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食品安全
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生物化学
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纳米技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）