A single pump column-switching technique coupled with polystyrene-divinylbenzene-carbon nanotubes column for the determination of trace anions in different concentrated organic matrices by ion chromatography

An ion chromatographic method with on-line sample pretreatment was developed for the trace analysis of seven common anions in concentrated matrices. The pretreatment column used in this study consisted of polystyrene-divinylbenzene (PS-DVB) and multi-walled carbon nanotubes (MWCNTs). It was too hydrophobic to retain different inorganic anions, but it showed a strong affinity for organic compounds. Thus, this chromatographic system could be used to detect trace anions in organic solvents, organic acids and relevant salts. The addition of MWCNTs decreased the surface areas of stationary phases and the retention times of organic matrices were shortened. Compared with conventional column-switching technique, only a single instrument (ICS2100) was needed in this system, including a pump, a conductivity detector, an eluent generator, a six-port valve and a ten-port valve. An electrochemical self-generating suppressor (ESGS) was adopted to convert the eluent of KOH into water for the matrix elimination. Two different eluent were employed in the chromatographic system, one for separation and the other for matrix elimination. The sample pretreatment and analysis were realized simultaneously. After optimization of this system, a calibration study was conducted by preparing and analyzing eight concentrations (between 5 and 5000 μg L(-1)) of mixture standards of seven anions in deionized water. The linearity was between 0.9990 and 0.9998, and the detection limits ranged from 0.41 to 3.17 μg L(-1). A spiking study was performed on three representative organic chemicals with satisfactory recoveries between 88.1% and 118.5% when the concentrations of the matrices did not exceed 10 g L(-1).     

Acid-Catalyzed Liquefaction of Bagasse in the Presence of Polyhydric Alcohol

Bagasse was subjected to a liquefaction process with polyethylene glycol/glycerol using sulfuric acid as catalyst. The effects of various liquefaction conditions, such as reaction time, liquefaction temperature, catalyst content, and liquid ratio (liquefaction solvents/bagasse), on the liquefied residue (LR) content and hydroxyl and acid numbers of liquefied products were investigated. The preferred liquefaction condition of bagasse was determined through orthogonal experiments. The results showed that the catalyst content and reaction time have a greater influence than liquid ratio and liquefaction temperature on the percentage of LR. The hydroxyl and acid numbers of the liquefied products were influenced by many factors, including liquefaction temperature, reaction time, acid content, and liquid ratio. The hydroxyl number of liquefied products decreased as the liquefaction reaction progressed, but the acid number of liquefied products increased. Based on the obtained data, the kinetics for liquefaction was modeled using the first-order reaction rate law and the apparent activation energy for the liquefaction of bagasse was estimated to be 38.30 kJ mol^?1.     

Production of acetic acid from liquid crystal display waste by use of a hydrothermal method

Because of the large quantity of liquid crystal displays (LCDs) in use, the volume of waste LCDs is ever-increasing, causing growing concern about their effective treatment. Polarizers are among the most important functional films used in LCDs and are mainly treated by incineration after being discarded. In this study, they were used to produce acetic acid under the hydrothermal conditions; this could aid development of a new environmentally sustainable process for treatment of waste polarizers. The experiment was performed in a 5.7-ml bath reactor heated by use of a salt-bath. The liquid product was analyzed by high-performance liquid chromatography. The effect of reaction temperature, reaction time, and oxidant on acetic acid production was investigated. Results showed that the yield and selectivity for acetic acid initially increased with increasing reaction temperature, reaction time, and H₂O₂ supply but then decreased within the ranges of the experiments performed. The highest acetic acid yield of 33.4 %, with selectivity of 26.7 % based on carbon, was obtained by hydrothermal treatment of waste polarizer at 350 °C for 5 min with 0.6 ml H₂O₂.     

铝盐配位分离氟碳铈矿酸浸液中氟和铈

氟碳铈矿是最主要的稀土来源,而氟是制约稀土清洁化分离的瓶颈,因此在提取稀土前进行氟的分离是一种解决方案。利用氟铝间很强的配位性质,加入铝盐而发生竞争配位反应,使[CeF2]2+变为游离Ce4+后向萃取相转移,实现氟-铈分离。实验结果表明:[H+]≤1.0mol.L-1,以Al2(SO4)3或NaAlO2为氟络合剂,根据酸浸中F-含量,向浸出液中加入n(F)/n(Al)=1的Al2(SO4)3或n(F)/n(Al)=1.5的NaAlO2时,氟-铈分离效果最好。     

Epitaxial superconducting δ-MoN films grown by a chemical solution method

The synthesis of pure δ-MoN with desired superconducting properties usually requires extreme conditions, such as high temperature and high pressure, which hinders its fundamental studies and applications. Herein, by using a chemical solution method, epitaxial δ-MoN thin films have been grown on c-cut Al(2)O(3) substrates at a temperature lower than 900 °C and an ambient pressure. The films are phase pure and show a T(c) of 13.0 K with a sharp transition. In addition, the films show a high critical field and excellent current carrying capabilities, which further prove the superior quality of these chemically prepared epitaxial thin films.     

手性碳量子点的制备及其应用

手性碳量子点(CQDs)因兼具优异的荧光性质、良好的生物相容性、较低的毒性、易于功能化以及手性特征等,在催化、检测和生物医学等领域具有广阔的应用潜力。目前,通过一步法或两步法制备的手性CQDs,已应用于手性催化、手性检测、高尔基体靶向成像、选择性调控酶和蛋白活性、选择性调控细胞能量代谢和促进植物生长等领域。然而,手性CQDs的发展初露头角,需进一步完善可控合成工艺,制备高荧光量子产率的长波长手性CQDs,使其在生物医学等领域绽放异彩。     

Combination of high‐resolution accurate mass spectrometry and network pharmacology provides a new method for the chemical constituents’ study and target prediction in vivo of Garcinia multiflora

Garcinia multiflora is a kind of evergreen tree which is widely distributed in the south of China. However, few researches focused on the constituents in different parts of G. multiflora as well as their potential targets and pathways in vivo. To clarify the chemical constituents of G. multiflora rapidly and predict the potential targets as well as pathways in vivo that this plant may have effects on, a feasible and accurate strategy was developed to identify the chemical constituents in fruits, leaves, and branches of G. multiflora by ultra‐high performance liquid chromatography with Q‐Exactive hybrid quadrupole‐orbitrap high‐resolution accurate mass spectrometry. Network pharmacology was then employed and a “compounds‐targets‐diseases” network was established. Sixty‐one compounds including polycyclic polyprenylated acylphloroglucinols, xanthones, and flavonoids were finally identified in different parts of G. multiflora, and the contents of seven constituents were quantified, respectively. On the basis of the network pharmacology analysis results, compounds in this plant were speculated to have potential pharmacodynamic effect on cancer, inflammatory, respiratory diseases, cardiovascular diseases, and metabolic diseases. This research will provide a new method for the advanced study on the pharmacodynamic materials basis of G. multiflora, and offer valuable evidences for medicinal purpose of this plant.     

Metabolic mapping of Schisandra chinensis lignans and their metabolites in rats using a metabolomic approach based on HPLC with quadrupole time‐of‐flight MS/MS spectrometry

Schisandra chinensis lignans are the main active components of the traditional Chinese medicine Schisandra chinensis in East Asia. At present, there are more and more medicines and health foods in which the total S. chinensis lignans extracts are considered as the main active components, but little research has been done on the active components of S. chinensis lignans in the blood and main target organs. In this study, the components of S. chinensis lignans in the blood, liver and brain tissues of rats at different time points after the intragastrical administration of S. chinensis lignans were determined by a metabolomic method based on high‐performance liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry spectrometry. Twelve Schisandra chinensis lignans and 15 metabolites in the blood, liver, and brain of rats were identified. The results showed that the main metabolic ways of S. chinensis lignans in rats were hydroxylation, demethylation, and demethylation‐hydroxylation, and some of them might undergo demethylation, dehydrogenation, epoxidation, and elimination reaction. The time‐dose characteristics of S. chinensis lignans and their metabolites in the blood and target organs were analyzed, which may be helpful to elucidate the active substances that really exert the pharmacodynamic effects of S. chinensis lignans in organisms.     

Rationally pairing photoactive materials for high-performance polymer solar cells with efficiency of 16.53%

The emergence of non-fullerene acceptors(NFA) offers a promising opportunity to develop high-performance donor/acceptor pairs with high power conversion efficiency,as NFAs offer tunable energy levels,broad absorption and suitable aggregation property.In order to enhance light-harvesting capability of active layers,we choose a wide bandgap polymer PTQ10 as the donor to blend with a narrow bandgap NFAY6 as the acceptor.In comparison with PTQ10:IDIC blend,~130 nm red-shifted absorption spectrum is observed in the PTQ10:Y6 blend,which potentially enhance the short-circuit current density(Jsc) for the PSCs.In addition,the optimal PTQ10:Y6 blend shows higher photoluminescence quenching efficiency and more efficient charge separation,higher charge mobilities,as well as weaker bimolecular recombination over the PTQ10:IDIC blend,which leads to an outstanding power conversion efficiency(PCE) of 16.53%,with a notable Jsc of 26.65 mA cm^-2 and fill factor(FF) of 0.751.     

Dual‐Pore Mesoporous Carbon@Silica Composite Core–Shell Nanospheres for Multidrug Delivery

Monodispersed mesoporous phenolic polymer nanospheres with uniform diameters were prepared and used as the core for the further growth of core–shell mesoporous nanorattles. The hierarchical mesoporous nanospheres have a uniform diameter of 200 nm and dual‐ordered mesopores of 3.1 and 5.8 nm. The hierarchical mesostructure and amphiphilicity of the hydrophobic carbon cores and hydrophilic silica shells lead to distinct benefits in multidrug combination therapy with cisplatin and paclitaxel for the treatment of human ovarian cancer, even drug‐resistant strains.