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1.
J Pharm Biomed Anal ; 246: 116198, 2024 May 07.
Article En | MEDLINE | ID: mdl-38754154

With the aging of the population, the prevalence of osteoporosis (OP) is rising rapidly, making it an important public health concern. Early screening and effective treatment of OP are the primary challenges facing the management of OP today. Quanduzhong capsule (QDZ) is a single preparation composed of Eucommia ulmoides Oliv., which is included in the Pharmacopoeia of the People's Republic of China. It is used to treat OP in clinical practice, but its mechanisms are unclear. This study involved 30 patients with OP, 30 healthy controls (HC), and 28 OP patients treated with QDZ to identify potential biomarkers for the early diagnosis of OP and to investigate the potential mechanism of QDZ in treating OP. The serum samples were analyzed using targeted amino acid metabolomics. Significant differences in amino acid metabolism were identified between the OP cohort and the HC group, as well as between OP patients before and after QDZ treatment. Compared with HC, the serum levels of 14 amino acids in OP patients changed significantly. Kynurenine, arginine, citrulline, methionine, and their combinations are expected to be potential biomarkers for OP diagnosis. Notably, QDZ reversed the changes in levels of 10 amino acids in the serum of OP patients and significantly impacted numerous metabolic pathways during the treatment of OP. This study focuses on screening potential biomarkers for the early detection of OP, which offers a new insight into the mechanism study of QDZ in treating OP.

2.
Anal Bioanal Chem ; 416(13): 3271-3280, 2024 May.
Article En | MEDLINE | ID: mdl-38584179

Accurate quantification of nano-selenium (nSe) and other ionic Se species in aquatic environments is a prerequisite for reliable estimation of their potential hazards. In this study, a micropore membrane filtration-based method followed by ICP-MS analysis was proposed for the selective concentration and determination of nSe in the water column. Polyvinylidene fluoride (PVDF) and nylon micropore filtration membranes were proven to efficiently capture nSe under optimal conditions (retention > 91.0 ± 0.87%). At the same time, ionic selenite and selenate could escape from the membranes, realizing the isolation of nSe and ionic Se species. The interference of dissolved organic matter (DOM) during separation can be resolved by adding Ca(II) ions, which can induce the formation of DOM aggregates by cation bridging effects. nSe retained on PVDF membranes could be effectively eluted with FL-70 (a powerful alkaline surfactant) aqueous solutions (0.5%, m/v) while maintaining the original size and morphology. Although nSe trapped on nylon membranes could not be easily eluted, quantification can also be achieved after membrane digestion. Speciation of ionic selenite and selenate in the filtrate was further conducted with an anion exchange column by using HPLC coupled with ICP-MS. The developed method was used to analyze Se species in six real water samples. Spiking experiments showed that the recoveries of nSe ranged from 70.2 ± 2.7% to 85.8 ± 1.3% at a spike level of 0.2 µg/L, and the recoveries of Se(IV) and Se(VI) ranged from 83.6 ± 0.5% to 101 ± 1% at a spike level of 0.55 µg/L, verifying the feasibility for the analysis of environmental water samples. This work provides possibilities to investigate the transformation and potential risks of nSe in the environment.

3.
Biomed Chromatogr ; 38(5): e5830, 2024 May.
Article En | MEDLINE | ID: mdl-38445357

Hong-Hua-Xiao-Yao tablet (HHXYT) is attracting attention increasingly because of its use in treatment of mammary gland hyperplasia (MGH) and menopausal syndrome. However, its pharmacokinetics remains unclear. This study developed a sensitive and rapid method for simultaneous determination of 10 compounds of HHXYT in rat plasma by liquid chromatography-tandem mass spectrometry and to compare the pharmacokinetics of these compounds in MGH rats and sham operated rats. The linearity, accuracy, precision, stability and matrix effect were within acceptable ranges. This established method was successfully applied to a pharmacokinetics study of 10 compounds in sham operated and MGH rats. According to the results, the bioavailability of glycyrrhetinic acid was highest in MGH rats and sham operated rats. The mean residence times of glycyrrhetinic acid and glycyrrhetinic acid 3-O-glucuronide were higher than those of the other compounds while the mean residence time and half-life of liquiritin, isoliquiritin and paeoniflorin were lower. Some pharmacokinetic parameters of ormononetin, liquiritigenin, isoliquiritigenin, liquiritin, isoliquiritin, paeoniflorin, protocatechuic acid and senkyunolide I were significantly different between MGH rats and sham operated rats. This study elucidated the dynamic changes of multiple components in rats after oral administration of HHXYT systematically and comprehensively, which provided guidance for clinical application.


Drugs, Chinese Herbal , Rats, Sprague-Dawley , Tandem Mass Spectrometry , Animals , Rats , Drugs, Chinese Herbal/pharmacokinetics , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/chemistry , Tandem Mass Spectrometry/methods , Reproducibility of Results , Female , Linear Models , Chromatography, Liquid/methods , Tablets/pharmacokinetics , Chalcones/pharmacokinetics , Chalcones/chemistry , Chalcones/blood , Biological Availability , Limit of Detection , Glycyrrhetinic Acid/pharmacokinetics , Glycyrrhetinic Acid/blood , Glycyrrhetinic Acid/chemistry
4.
Phys Chem Chem Phys ; 26(3): 2449-2456, 2024 Jan 17.
Article En | MEDLINE | ID: mdl-38168706

The search for highly active and low-cost single-atom catalysts for the oxygen reduction reaction (ORR) is essential for the widespread application of proton exchange membrane fuel cells. Transition metals anchored on nitrogen-doped graphdiyne (GDY) have attracted considerable interest as potentially excellent catalysts for the ORR. However, the relationship between the active site and nitrogen-doped GDY remains unclear. In this work, we conducted a systematic investigation of sp-hybridized N atoms anchoring single transition metal atoms of 3d and 4d on GDY (TMC2N2) as electrocatalysts for the ORR. Firstly, 18 kinds of TMC2N2 were determined to have good thermodynamic stability. Due to the extremely strong adsorption of *OH, TMC2N2 exhibits inferior ORR performance compared to traditional Pt(111). Considering that *OH adsorption hinders the catalytic activity of TMC2N2, we modified the OH ligand of TMC2N2 to develop the high-valent metal complex (TMC2N2-OH) aiming to enhance the electrocatalytic activity. The adsorption of intermediates on most TMC2N2-OH is weakened after the modification of the OH ligand, especially for the adsorption of *OH. Thus, by comparing the ORR overpotential of catalysts before and after ligand modification, we find that the catalytic activity of different TMC2N2-OHs improves to various degrees. MnC2N2-OH, TMC2N2-OH, and TcC2N2-OH exhibit relatively high ORR catalytic activity, with overpotentials of 0.93 V, 1.19 V, and 0.92 V, respectively. Furthermore, we investigated the cause of improved catalytic activity of TMC2N2-OH and found that the modified coordination environment of the catalyst led to adjusted adsorption of ORR intermediates. In summary, our work sheds light on the relationship between nitrogen-doped GDY and transition metal sites, thus contributing to the development of more efficient catalysts.

5.
ACS Omega ; 8(49): 46589-46597, 2023 Dec 12.
Article En | MEDLINE | ID: mdl-38107970

Hydroxyl (OH) radicals, as common radicals in aqueous environments, play an important role in inducing the degradation reactions of polymers. However, understanding the fundamental mechanisms of radical-induced degradation of polymers at the atomic level remains a formidable challenge. In this study, we employ density functional theory to investigate the geometric and electronic structural properties of polyacrylamide (PAM) in (-CH2CHCONH2-)n (n = 2-6) complexes. Additionally, we explore the degradation mechanism of the n = 4 complex induced by the OH radical. The results indicate that there are three sites for the initial reaction (R1 and R2 are at the ends and R3 is in the middle). The OH radical removes a H atom from the PAM main chain and simultaneously triggers a single-electron-transfer process on the same chain. This process significantly reduces the dissociation energy barrier of the C-C bond in the PAM chain, from ∼90 to ∼20 kcal/mol. Specifically, when the induced reaction occurs at the end of the chain, a series of broken bonds will appear only along the main chain. While it happens in the middle, the broken bonds will exist simultaneously along both the main and side chains. Our results reveal the importance of OH radicals in polymer dissociation, particularly in PAM, and emphasize the degradation mechanism of SET.

6.
Nat Prod Res ; : 1-8, 2023 Nov 30.
Article En | MEDLINE | ID: mdl-38031803

Callicarpa nudiflora (C. nudiflora) is widely used in the treatment of bleeding related diseases. However, its main material basis has not been fully defined which limits the in-depth study of screening out the material basis of hemostasis and coagulation from C. nudiflor. In this study, the method of spectrum-effect relationship was used to quickly screen the material basis of hemostasis and coagulation. The five compounds related to hemostasis and coagulation were screened as Alyssonoside (P24), Luteolin (P25), Quercetin (P26), Apigenin (P28), Isorhamnetin (P29). And the contribution of these five peaks to hemostasis and coagulation efficacy was P24 > P25 > P28 > P26 > P29.

7.
Phys Chem Chem Phys ; 25(42): 29173-29181, 2023 Nov 01.
Article En | MEDLINE | ID: mdl-37870382

Seeking cost-effective and earth-abundant electrocatalysts with excellent activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in zinc-air batteries (ZABs) is critically important. In this work, the ORR and OER performance of the Fex cluster supported on FeN4 composite sites (FeN4@Fex) is investigated based on density functional theory. Based on the charge density difference between the Fex cluster and the FeN4 substrate, the conclusion that the decreased charge density of the chemical bond between the metal and the adsorbate can weaken the adsorption of the adsorbate can be drawn. The results of the d-band center also confirm this. Furthermore, the ORR and OER free energy change profiles show that FeN4@Fe8 exhibits the best ORR and OER activity. This is because the electronic environment regulated by the Fex cluster can improve the adsorption of intermediates, which is conducive to enhancing catalytic activity. Further considering the solution environment, the activity of FeN4@Fex with preadsorbed OH (FeN4@Fex(OH)y) was studied. It is found that FeN4@Fe8(OH)6 is still the best catalyst. This work introduces new highly active composite sites for catalyzing the ORR in an acid medium.

8.
NanoImpact ; 31: 100478, 2023 Jul.
Article En | MEDLINE | ID: mdl-37499754

Due to the growing number of the world's population, there is an urgent need for high-quality food to meet global food security. Traditional fertilizers and pesticides face the problems of low utilization efficiency and possible hazards to non-target organisms. Selenium (Se) is an essential trace element for animals and humans. As a result, Se nanoparticles (SeNPs) have aroused intense interest and found opportunities in agricultural use. Herein, we summarized representative studies on the potential application of SeNPs in agriculture, including mitigating biotic and abiotic stresses in plants, promoting seed germination and plant growth, and improving Se contents and nutritional values in crops, and the underlying mechanisms were also discussed. Finally, future directions are highlighted to get a deep insight into this field.

9.
Chem Biodivers ; 19(10): e202200444, 2022 Oct.
Article En | MEDLINE | ID: mdl-36066484

Callicarpa nudiflora, belonging to the family Verbenaceaae, is wildly used as a traditional Chinese herbal medicine (Luo-hua-zi-zhu) for hemostasis, antibiosis and antiphlogosis in clinic. However, the underlying chemical basis of C. nudiflora for the significant effects remains obscure. Hence, an ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry method was established for the characterization of multi-constituents in C. nudiflora. As a result, 57 chemical compounds were identified based on their retention times, accurate masses and MS/MS data, and 20 of them were uncovered for the first time in C. nudiflora. In addition, an optimized UHPLC fingerprint analysis, combined with chemometrics including similarity analysis, principal component analysis and partial least squares-discriminant analysis was developed for quality assessment and origin discrimination of C. nudiflora. Multivariate data analysis revealed the resemblances and differences of C. nudiflora related to regions, while partial least squares-discriminant analysis screened nine characteristic markers including luteoloside, acteoside, luteolin-4'-O-ß-D-glucopyranoside, pachypodol, isoquercitrin, nudifloside, 5,7,3',4'-tetrahydroxy-8-methoxy-6-C-ß-D-glucopyranosylflavone, 7α-acetoxysandaracopimaric acid and sandaracopimaric acid which contributed the most to the classification. This was the first report on the comprehensive profiling of chemical components in C. nudiflora, which helped to uncover the material basis of C. nudiflora and possess potential value for quality evaluation and clinical application purpose.


Callicarpa , Drugs, Chinese Herbal , Callicarpa/chemistry , Tandem Mass Spectrometry , Luteolin , Chromatography, High Pressure Liquid/methods , Drugs, Chinese Herbal/chemistry
10.
J Pharm Pharmacol ; 74(11): 1598-1608, 2022 Nov 04.
Article En | MEDLINE | ID: mdl-36106815

Objectives Due to its high morbidity, high mortality, and high disability, stroke has been the first cause of death and the major cause of adult disability in China. Natural borneol has been widely utilized in Traditional Chinese Medicine to promote drug absorption. Formononetin is a natural isoflavonoid with potent neuroprotective activity but poor brain delivery. Methods This study aimed to screen the optimum proportion that natural borneol promotes formononetin entry into the brain, evaluate the anti-cerebral ischaemia efficacy of formononetin/natural borneol combination in middle cerebral artery occlusion/reperfusion model rats, and clarify the possible mechanism for natural borneol's promoting formononetin delivery in the brain. Key findings Our studies exhibited that natural borneol remarkably promoted formononetin entry into the brain when combined with formononetin in a 1 : 1 molar ratio and notably improved neuro-behavioural scores and reduced the infarct of middle cerebral artery occlusion/reperfusion model rats. This study further discovered that the enhanced anti-cerebral ischaemia effect resulted from natural borneol increasing the permeability of the blood-brain barrier to elevate formononetin concentration in the brain rather than the pharmacodynamic synergy or addition between formononetin and natural borneol. Conclusions The study provides a good strategy to screen drug combinations for the treatment of brain disease by combining natural borneol with other drugs.


Brain Ischemia , Reperfusion Injury , Animals , Rats , Infarction, Middle Cerebral Artery/drug therapy , Camphanes/pharmacology , Brain Ischemia/drug therapy , Brain , Reperfusion Injury/drug therapy
11.
Anal Methods ; 14(6): 672-677, 2022 02 11.
Article En | MEDLINE | ID: mdl-35088063

The sensitive determination of the critical micelle concentration (CMC) of surfactants is very important for their practical application. Due to their good sensitivity and simple operation, pyrene and its derivatives have been widely used as fluorescent probes to detect the CMC. However, their virulent and poor water-soluble nature has limited their wide employment. In the present work, environmentally friendly amphiphilic carbon dots (Cdots) with dual-color emission and absolute quantum yield (PLQY) values higher than 50% have been fabricated through a solvothermal process, which could successfully serve as self-calibrative, ratiometric fluorescent probes to estimate the CMC of both non-ionic and ionic surfactants. This work not only provides a new strategy to design green ratiometric fluorescent probes for the CMC measurement of surfactants but also expands the application of Cdots in the colloidal field.


Carbon , Quantum Dots , Fluorescent Dyes , Micelles , Surface-Active Agents
12.
Front Pharmacol ; 12: 806808, 2021.
Article En | MEDLINE | ID: mdl-35153761

Callicarpa nudiflora (C. nudiflora) is widely used to treat inflammation-related diseases in China. C. nudiflora mainly contains phenylethanol glycosides, flavonoids, triterpenes, diterpenes, iridoid glycosides, volatile oils, and other small molecules. Therefore, it is necessary to screen out anti-inflammatory active substances from C. nudiflora. In this paper, high-performance liquid chromatography was used to establish the fingerprint of C. nudiflora extracts. The anti-inflammation of C. nudiflora extracts were evaluated by the experiment of toes swelling in inflammatory rats. Then, the spectrum-effect relationship between the fingerprints and anti-inflammatory activities was researched by Pearson analysis and orthogonal partial least squares analysis to identify a group of anti-inflammatory compounds of C. nudiflora extracts. The differences of extracts are illustrated by principal component analysis and cluster analysis in pharmacological effects. Finally, 12 compounds, including catalpol (P1), caffeic acid (P2), protocatechuic acid (P9), 3,4-dihydroxybenzaldehyde (P10), forsythiaside E (P12), protocatechualdehyde isomers (P14), forsythiaside B (P15), rutin (P16), alyssonoside (P21), verbascoside (P22), 2'-acetyl forsythoside B (P24), and isorhamnetin (P32) by HPLC-DAD and UPLC-Q-TOF MS/MS, were determined as potential compounds for anti-inflammatory activity in C. nudiflora. In particular, six compounds were identified as active substances with the greatest anti-inflammatory potential. Moreover, all compounds were tested for anti-inflammatory experiments or anti-inflammatory literature retrieval. In this study, a method for rapid screening of potential anti-inflammatory active ingredients of C. nudiflora was established, which can provide a reference for the future study of active compounds of C. nudiflora.

13.
Zhongguo Zhong Yao Za Zhi ; 45(8): 1800-1807, 2020 Apr.
Article Zh | MEDLINE | ID: mdl-32489063

The difference in pharmacological activities and active components between leaves, barks and flowers of Eucommia ulmoides(EU) are still unclear. However, clarifying the differences in pharmacological effects of different parts of EU is of great significance for the development of EU products, and their corresponding active components provide basis for quality control of different parts of EU. Based on the chemical compositions of different parts of EU, integrated strategy of target prediction and target analysis of the compounds was used to investigate the difference in the pharmacological effects of leaves, barks and followers. The "component-target-function" association network was constructed to mine the specific material basis corresponding to specific efficacy of different parts of EU. In this study, the author found that EU may have the activities of anti-oxidation, neuromodulation, blood pressure regulation, myo-cardial expansion, and anti-apoptosis according to target prediction and function analysis. However, the effects of different parts of EU were different. Leaves were involved in the process of bone development such as osteoblast differentiation and bone mineralization in a specific way. In addition, the leaves may affect the process of bone development by regulating the metabolism of vitamin D and affecting the absorption of calcium. Leaves may also specifically act on estrogen and estradiol response processes where estrogen receptors were involved. Regarding its protective function for the liver, leaves may play a role by regulating vitamin A-related pathways. As compared with leaves, the specific pharmacological effects of barks may be related to the development of the urinary system. Flowers specifically participate in functions related to pain sensation, glutamate signaling pathway, and excitatory postsynaptic potential. Based on the hie-rarchical network of "component-target-pathway", we further found that specific activities of different parts of EU were inseparable from its specific chemical compositions. Phenylpropanoids, terpenoids and rings, iridoids, flavonoids and other components which are specific in leaves can target the specific effects of leaves, while the flavonoids in barks and the quinones in flowers may be the material basis for their respective specific effects. The prediction of the activities of different parts of EU provides a new basis for the focuses and differences in subsequent Eucommia product development. At the same time, the material basis research based on differential efficacy also provides a basis for the quality control of Eucommia differentiated products.


Eucommiaceae , Pharmaceutical Preparations , Flavonoids , Iridoids , Plant Leaves
14.
Zhongguo Zhong Yao Za Zhi ; 45(3): 497-512, 2020 Feb.
Article Zh | MEDLINE | ID: mdl-32237506

To date, 205 compounds have been identified from different medicinal parts of Eucommia ulmoides, including lignans, iridoid terpenoids, phenols, flavonoids, terpenoids and steroids, polysaccharides and others. Their pharmacological effects include blood pressure-lowering, blood sugar-lowering, blood lipids-regulating, prevention of osteoporosis, anti-inflammation, liver protection, anti-cancer and so on. Their efficacy and mechanism from different parts are slightly different. In this paper, the chemical composition, pharmacological action and mechanism of different parts of E. ulmoides were systematically summarized, as well as its quality control and processing research, to provide theoretical basis for further rational development and utilization of E. ulmoides.


Eucommiaceae/chemistry , Phytochemicals/chemistry , Phytochemicals/pharmacology , Flavonoids , Iridoids , Lignans , Phenols , Plants, Medicinal/chemistry , Polysaccharides , Steroids , Terpenes
15.
Ecotoxicol Environ Saf ; 183: 109471, 2019 Nov 15.
Article En | MEDLINE | ID: mdl-31377520

Present study described a magnetic adsorption and removal method with prepared magnetic core-shell Fe3O4@polyaniline microspheres for the removal of two typical BFRs, tetrabromobisphenol-A (TBBPA) and decabromodiphenyl ether (BDE-209) from water samples. Magnetic core-shell Fe3O4@polyaniline microspheres were prepared by a hydrothermal and two step polymerization method with cheap iron salts and aniline, which were characterized with transmission electron microscopic (TEM) and scanning electron microscopy (SEM). The results showed that the Fe3O4@polyaniline microspheres earned a clear thickness shell of polyaniline (about 50 nm) and a saturation magnetization of 40.4 emu g-1. The Magnetic core-shell Fe3O4@polyaniline exhibited excellent adsorption capability and removal rate to TBBPA and BDE 209. The adsorption of TBBPA and BDE 209 all followed pseudo-second order kinetics and agreed well to the Freundlich adsorption isotherms model. The negative Gibbs free energy change (ΔG0) and positive standard enthalpy change (ΔH0) for TBBPA and BDE-209 suggested that the adsorption was spontaneous and endothermic in nature. These results demonstrated that Fe3O4@PANI was a good adsorbent and would have a good application prospect in the removal of pollutants from environmental water.


Aniline Compounds/chemistry , Halogenated Diphenyl Ethers/analysis , Magnetite Nanoparticles/chemistry , Nanocomposites/chemistry , Polybrominated Biphenyls/analysis , Water Purification/methods , Adsorption , Kinetics , Water , Water Pollutants, Chemical/analysis
16.
J Hazard Mater ; 371: 323-331, 2019 06 05.
Article En | MEDLINE | ID: mdl-30856443

Fe3O4@polyaniline, a Fe3O4-based magnetic core-shell material, was synthesized and its morphology and microstructure were characterized with transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry. Polyaniline was modified onto the surface of Fe3O4 nanoparticles by a self-assembly method based on a two-step oxidative polymerization method. The new materials exhibited good adsorption to polycyclic aromatic hydrocarbons such as fluoranthene, pyrene and benzo[a]pyrene from environmental water samples due to the high affinities of polyaromatic hydrocarbons to polyaniline via π-π and van der Waals interactions. The experimental results indicate that the adsorption of polyaromatic hydrocarbons follows pseudo-second order kinetics and the adsorption isotherms conform to a Langmuir isotherm model. The thermodynamic parameters for polyaromatic hydrocarbons indicate that the adsorption process is spontaneous and endothermic in nature, but adsorption occurs via non-covalent interactions. This study indicated that the Fe3O4@polyaniline hybrid core-shell structure was proved to be a good adsorbent for polyaromatic hydrocarbons while exhibiting simple preparation, easy separation, low cost, high reusability and great potential applicability for removal of polyaromatic hydrocarbons from water.

17.
Sci Rep ; 7(1): 11316, 2017 09 12.
Article En | MEDLINE | ID: mdl-28900228

In this study, we fabricated a novel material composed of magnetic graphene oxide incorporated Fe3O4@polyaniline (Fe3O4@PANI-GO) using a modified Hummers' method, solvothermal, and two-step polymerisation method. The resulting products were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results indicated that magnetic Fe3O4@PANI particles were successfully loaded onto the surface of the graphene oxide. Further Fe3O4@PANI-GO was investigated to remove bisphenol A(BPA), α-naphthol, and t-octyl-phenol (t-OP) from water samples by magnetic solid phase extraction. Under the optimal conditions, the Fe3O4@PANI-GO composite exhibited good adsorption capacity for t-OP, BPA, and α-naphthol, and the adsorption of these followed a pseudo-second-order kinetic model. Adsorption isotherms fit the Langmuir model, and the adsorption was an endothermic and spontaneous process. This work indicated that Fe3O4@PANI-GO earned great application prospect for removing phenolic contaminants from polluted water.

18.
Talanta ; 156-157: 196-203, 2016 Aug 15.
Article En | MEDLINE | ID: mdl-27260453

The magnetic nanomaterial Fe@polyethyleneimine (Fe@PEI) was successfully synthesized and used as an effective adsorbent material for magnetic solid phase extraction(MSPE) of As(III) and As(V) from water samples. Fe@SiO2 nanoparticles were prepared by one pot synthetic method using a borohydride reduction method, then modified with (3-chloropropyl)trimethoxysilane to obtain Fe@SiO2-Cl by chloropropylation, which was reacted with PEI to achieve Fe@polyethyleneimine (Fe@PEI). The microstructure and morphology of Fe@PEI were characterized by transmission electron microscoscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The experimental results showed that Fe@PEI demonstrated excellent adsorption for As(III) and As(V). Based on this fact, the determination method for these two arsenic species earned good limits of detection (LODs) of 0.002µgL(-1) and wide calibration curves in the concentration range from 0.008 to 0.2µgL(-1). The precisions of As (III) and As (V)were 1.95% and 2.55% (RSD, n=6), respectively. The proposed method was validated with real samples and the spiked recoveries were in the range of 82.7-98.3% and the accuracies were in the range of 2-13.3%. The results demonstrated that the developed MSPE method had good advantages such as simplicity, rapid separation, low cost, easy to reuse and high-quality analytical performances, which made it attractive for rapid and efficient extraction of inorganic arsenic species in the environmental water samples.

19.
Anal Bioanal Chem ; 408(19): 5211-20, 2016 Jul.
Article En | MEDLINE | ID: mdl-27178558

In this work, polyethyleneimine grafted silica-coated nanoscale zero valent iron (Fe@SiO2@PEI) has been successfully synthesized and was investigated to be an effective adsorbent for efficient enrichment of five phthalate esters such as diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, diphenyl isophthalate, and dicyclohexyl phthalate (DPP, DBP, BBP, DPIP, and DCHP) from environmental water samples. The structure and morphology of the materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction(XRD). The parameters that influenced the enrichment performance such as amount of sorbent, sample pH, type of eluent, volume of eluent, salting-out effect, adsorption time, and desorption time were investigated. Under optimal conditions, excellent linear relationships were found in the concentration range from 0.5 to 100 µg L(-1), the limits of detection (S/N = 3) were in the range of 0.26-0.45 µg L(-1), and the intra-day and inter-day precisions (n = 6) were in the range of 3.7-4.8 and 3.2-4.3 %, respectively. The developed method was evaluated with real water samples, and satisfied spiked recoveries in the range of 99-104 % were achieved. The experimental results proved that Fe@SiO2@PEI had good adsorption for phthalate esters, and would be a good adsorbent for the magnetic solid-phase extraction of important pollutants from environmental water samples.ᅟ Graphical abstract A flowchart of the synthesis of polyethyleneimine grafted silica coated nanoscale zero valent iron (Fe@SiO2@PEI) and the process of the developed magnetic solid phase extraction of phthalate esters before the analysis by high performance liquid chromatography.

20.
Adv Mater ; 27(26): 3962-8, 2015 Jul 08.
Article En | MEDLINE | ID: mdl-26037719

A strategy for preparing hybrid carbon structures with amorphous carbon clusters as hard building blocks by compressing a series of predesigned two-component fullerides is presented. In such constructed structures the building blocks and their boundaries can be tuned by changing the starting components, providing a way for the creation of new hard/superhard materials with desirable properties.

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