Determination of Ten Kinds of Alpha-2 Agonists Residues in Animal Derived Food by UHPLC-Triple Quadrupole/Composite Linear Ion Trap Mass Spectrometry

[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.

Transport of Ca^(2+) Ion through a Bubbling Pseudo-emulsion Liquid Membrane with Calixarenes and Calixcrowns as Carriers

Several new calixcrowns were synthesized and characterized. The transport of Ca 2+ ion was investigated through a bubbling pseudo emulsion liquid membrane with these calixcrowns, the parent calixarenes ( n =4, 6, 8) and the ester, acid derivatives of calixarene as mobile carriers. The effects of the initial concentrations of Ca 2+ ion in the source phase and the initial pH difference (ΔpH) between the receiving phase and the source phase were studied. The results suggest that there are two different transport mechanisms. The transports using calixarenes and their ester, acid derivatives as carriers represent a proton coupled co transport with a flow of protons in the opposite direction, while the transports using the calixcrowns as carriers exhibit the characteristics of an anion coupled co transport with a flow of anion in the same direction.

Energy properties and spatial plume profile of ionic liquid ion sources based on an array of porous metal strips

An ionic liquid ion source(ILIS)is a kind of high brightness ion source capable of providing high-speed positive or negative ion beams.This paper presents a miniaturized ILIS based on an array of porous metal strips.The porous emitter array,integrated with seven 10 mm long strips,is fabricated using wire electrical discharge machining(WEDM)combined with electrochemical etching.The assembled ILIS is 30 mm×30 mm×17.5 mm in size and weighs less than 25 g.A series of experiments,including anⅠ-Ⅴcharacteristic test,a retarding potential analyzer(RPA)test,and a spatial plume distribution test,have been conducted in vacuo to characterize the performance of the ILIS.Results show that the emitted current is up to about 800μA and ion transparency is as high as 94%.Besides,RPA curves reveal that the total fragmentation rate of the emitted particles accounts for 48.8%in positive mode and 59.8%in negative mode.Further,with the increase in applied acceleration voltage,the voltage loss rises while the energy efficiency decreases.It is also found that the plume perpendicular to the strips has a higher divergence than the one parallel to the strips.A numerical simulation by COMSOL reveals that the electric field distribution between the two electrodes results in such a spatial plume profile.

An ionic liquid supported CeO_2 nanoparticles-carbon nanotubes composite-enhanced electrochemical DNA-based sensor for the detection of Pb^(2+)

An electrochemical sensor incorporating a signal enhancement for the determination of lead （II） ions （Pb2＋） was designed on the basis of the thrombin-binding aptamer （TBA） as a molecular recog- nition element and ionic liquid supported cerium oxide （CeO2） nanoparticles-carbon nanotubes compo- site modification. The composite comprises nanoparticles CeO2, multi-waU carbon nanotubes （MWNTs） and hydrophobic room temperature ionic liquid （RTIL） 1-ethyl-3-methylimidazolium tetrafluoroborate （EMIMBF4）. The electrochemical sensors were fabricated by immersing the CeOa-MWNTs-EMIMBF4 modified glassy carbon electrode （GCE） into the solution of TBA probe. In the presence of Pb2＋, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2＋ and TBA. The TBA-bound Pb2＋ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2＋. The reduction peak current is linearly related to the concentration of Pb2＋ from 1.0 ＊ 10-8 M to 1.0 ＊ 105 M with a detection limit of 5 ＊ 109 M. This work demonstrates that the CeOz-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobi- lizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.

Ionic liquid-assisted hydrothermal synthesis of SnS nanoparticles:Electrode materials for lithium batteries,photoluminescence and photocatalytic activities

Tin mono-sulphide（Sn S） nanoparticles（Nps） have been successfully synthesised through ionic liquid assisted hydrothermal method using hydrated tin（II） chloride as a precursor, thiourea as sulphur source precursors using 2-Methoxy ethyl methyl imidazolium methane sulfonate ionic liquid as co-solvent. The Reitveld refinement on powder X-ray diffraction（PXRD） confirmed the presence of orthorhombic Sn S structure as major phase along with traces amount of Sn S2 and Sn2 S3. Diffuse reflectance spectrum studies revealed the energy band gap around 1.38 e V. TEM images confirmed the Sn S Nps with average particle size of 40 nm and HRTEM suggest good crystallinity. The electrochemical property for lithium storage behaviour shows an initial discharge capacity of 658 m Ah/g and it retains discharge capacity of 426 m Ah/g for 16 cycles, at current density 100 m A/g. The obtained results indicate that Sn S Nps to be one of the possible promising anode materials for next generation Lithium batteries. Photoluminescence study of Sn S Nps shows a strong green emission at 530 nm. Sn S Nps were also tested for the photocatalytic adsorption of methylene blue and Rhodamine B.

Investigation of the Lipophilicity of 2-Benzoylpyridine-Thiosemicarbazone Based on the Ion Transfer across the Liquid/Liquid Interface

The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.

THE STUDY ON THE MASS TRANSFER MECHANISM OF EUROPIUM ION THROUGH LIQUID SURFACTANT MEMBRANES

The transfer of trivalent europium ion in a liquid surfactant membrane system is investigated in order toclarify the characteristics of liquid membrane separation process and the availability of this technique forrecovering trivalent lanthanides and actinides.A layered structure model for the emulsion globule is sug-gested.The equations describing the relationship among the effective membrane thickness,the time andother factors are derived and verified experimentally.Results show that under certain conditions the decreas-ing concentration of europium ion in the external phase is proportional to the square root of the time,the acidity of the internal phase and the carrier concentration in the membrane phase.The membrane phase consists of kerosene（solvent）,Span-80（surfactant）and di-（2-ethylhexyl） phosphoricacid（HDEHP,carrier）.The internal phase is dilute nitric acid and the external phase is aqueous solu-tion containing Eu（NO3）3.The mass transfer rate of europium in this system is high and the recovery ofeuropium may be more than 99%.

Influence of amphotericin B on liquid crystal state of the Cholesterol/Dipalmitoylphosphatidylcholine monolayer in the presence of different metal cations

Amphotericin B is a very effective antifungal drug,but it has an adverse reaction to the membrane of mammals＇ cells.The interaction between Am B and cholesterol（Chol） causes the formation of pores on the membrane to destroy its integrity.In particular,Am B has a significant effect on the permeability of membrane for K~＋ions.It has been reported that Na＋ions and Ca^（2＋）ions may have some influence on the interaction between amphotericin B and lipid molecules.In this work,the effects of these metal cations on the physical state and intermolecular interaction of the Cholesterol/Dipalmitoylphosphatidylcholine（Chol/DPPC） monolayer with and without Am B have been investigated.The addition of Am B induces the change of physical state of the lipid monolayer from liquid-gel phase to liquid phase.Different metal cations could influence the phase transition of the Am B-lipid monolayer.The K~＋ions and Ca2＋ions make the obvious phase transition disappear.However,the presence of Na＋ions has little influence on the phase transition of the Am B-lipid monolayer.The addition of Am B and the presence of different metal cations weaken the attractive force on the monolayers.After addition of Am B,the force between the molecules is the strongest in the environment of K＋ions,thus is the weakest in the environment of Ca^（2＋）ions,which may be due to the distribution of these metal cations inside and outside of cells.A large number of K＋ions distribute inside of the cells,thus most of Na＋and Ca^（2＋）ions exist out of the cells.Hence,it may be possible that when Am B molecules are out of the cells,the reaction between the drug and lipid molecules is weaker than that inside the cells.These results may have a great reference value for further studying the toxicity mechanism of Am B and the influence of metal cations on the membrane.

Solid-liquid solvent extraction of metal ions

An overview of extraction of some trace metal ions using molten solvent (lowmelting substance) during last two decades is presented. The development of this technique since itsinception is briefly traced. The comparison of extraction efficiency, thermodynamics and kineticsmainly involving extraction of rare earth ions between molten solvent extraction at high temperatureand usual liquid-liquid extraction at room temperature are discussed in detail. The variousparameters obtained from the previous and present studies such as equilibrium extraction constantK_(ex), pH_(1/2), thermodynamic and kinetic data are displayed in tabular form. Finally, the currentdemands, disadvantages and future prospects are also evaluated.

Screening for Plant Toxins in Honey and Herbal Beverage by Ultrahigh-Performance Liquid Chromatography-Ion Mobility-Quadrupole Time of Flight Mass Spectrometry

The standards of plant toxins were separated by a C18 column with gradient elution with 0.1% formic acid/water (V/V) and 0.1% formic acid/acetonitrile (V/V) as mobile phase and acquired by ion mobility-quadrupole time of flight mass spectrometry (IM-QTOF MS) in positive ion mode. A database of 308 plant toxins including retention time, collision cross-section (CCS) and its fragment ions was established. Honey dissolved in water or herbal beverage was extracted by acetonitrile and purified with PSA sorbent, and then acquired by ultrahigh-performance liquid chromatography IM-QTOFMS. The acquired data were processed by comparing with the database we established to confirm the target compounds. The average recoveries for samples at two levels ranged from 60.6% - 120.1%, with relative standard deviation (n = 6) less than 25%. The limit of quantitation for plant toxins ranged from 1 - 20 μg/kg. The developed screening method was used in determination of honey, herbal beverage and honey flavored tea beverage samples. The results showed that berberine was detected in one honey with 1 μg/kg and caffeine was present in some beverages with the concentration from 200 and 5500 μg/kg. This method could meet the requirement for rapid screening of plant toxins in honey and herbal beverage. It can be used for the quality control of honey and herbal beverage in enterprises or quality inspection departments. It also can be used in the rapid screening of food poisoning.

Preparation and Properties of Lanthanum Trivalent Ion Doped TiO_2 Nanopowders by Liquid Plasma Spray

The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size.

Modification to solution-diffusion model for performance prediction of nanofiltration of long-alkyl-chain ionic liquids aqueous solutions based on ion cluster

Mathematical modeling for nanofiltration of ionic liquids(ILs) solutions could assist to understand transfer mechanism and predict experimental values. In this work, modeling by solution-diffusion model for nanofiltration of long-alkyl-chain ILs aqueous solutions was proposed. Molecular simulations were performed to validate the existence of ion cluster in long-alkyl-chain ILs aqueous solution. Based on the results of simulations, parameters used in the solution-diffusion model were modified, such as concentration of ILs and diameter of ion cluster.The modeling process was developed for three long-alkyl-chain ILs aqueous solutions with different concentrations(1-alkyl-3-methylimidazolium chloride: [C6 mim]Cl, [C8 mim]Cl, [C10 mim]Cl). The calculated values obtained from modified solution-diffusion model could well match the experimental values.

Safety Assessment of Ionic Liquid-Based Lithium-Ion Battery Prototypes

In this paper we report the results of combined cycle- and life-aging and abuse tests carried out under severe conditions on Li4Ti5O12/LiFePO4 lithium-ion stacked prototypes using a PYR14 FSI-LiTFSI ionic liquid electrolyte. No relevant degradation phenomena took place within ionic liquid electrolyte during prolonged inactivity period or overcharging. No fire/explosion or venting event as well as no gas development occurred during abuse tests, which led only to modest raise in temperature. Therefore, electrodes based on Li4Ti5O12 and LiFePO4 active materials can be favorably combined with non-volatile and non-flammable pyrrolidinium FSI ionic liquid electrolytes to realize highly safe lithium-ion battery systems.

固相萃取-超高效液相色谱-三重四极杆/线性离子阱质谱法检测水中大环内酯类抗生素

采用固相萃取-超高效液相色谱-三重四极杆线性离子阱质谱技术(SPE-UPLC-QTRAP MS)建立了环境水样中阿奇霉素、林可霉素、克林霉素、红霉素及替米考星5种大环内酯类抗生素的检测方法。调节水样pH为10后经HLB固相萃取柱净化、富集,然后用Kinetex F5色谱柱进行分离,用0.1%甲酸水溶液和0.1%甲酸乙腈溶液进行洗脱,采用电喷雾正离子源(ESI+),多反应监测(MRM)-信息依赖采集(IDA)-增强子离子(EPI)扫描模式对样品进行检测,用多反应监测(MRM)进行定量,增强子离子(EPI)谱图库辅助定性。结果表明:5种大环内酯类抗生素线性关系良好,相关系数均大于0.9992;检出限为0.01~0.30μg·L^(-1),定量限为0.10~0.50μg·L^(-1);3种不同浓度的水样加标回收率为71.60%~111.05%,相对标准偏差均在10%以内,EPI谱库比对纯度值均大于90%。该方法将传统的MRM扫描模式结合EPI谱图库检索,实现了同时定性和定量分析,对未知物准确定性定量检测提供了重要参考。

Electrochemical View of the Band Gap of Liquid Water for Any Solution

Studying liquid water in a frame of band theory shows that varying a reduction-oxidation (RedOx) potential of aqueous solution can be identified as shifting Fermi level in its band gap. This medium becomes the reductive one when Fermi level is shifting to the conduction band due to populating hydroxonium level (H3O+/ H3O) by electrons and transforming water in a hypo-stoichiometric state, H2O1-│X│. Opposite in the hyper-stoichiometric one H2O1+│X│ Fermi level is shifting to the valence band due to populating hydroxide level OH/OH- by holes and the aqueous solution becomes the oxidative one. The energy difference between these electronic levels is estimated of 1.75 eV. It is shown that the standard half-reactions and the typical aqueous electrodes fix their RedOx potential only by the electrons and holes populations ([H3O],[OH]) of these local electronic levels in the band gap of non-stoichiometric water in the corresponding solutions.

Transport of yttrium metal ions through fibers supported liquid membrane solvent extraction

A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liquid membrane was impregnated with different concentrations carrier.The experimental variables explored were concentration of yttrium(Ⅲ) ions,pH of source phase,PC-88A concentration in membrane phase,acid concentration in receiving phase and stirring speed.The pre-concentration of yttrium(Ⅲ) ions ...

离子液体在电极材料制备中的应用研究进展

离子液体因具有种类丰富、结构可设计性强、表面张力小等特点,在电极材料制备中表现出独特的性质.围绕着离子液体作为绿色溶剂在电极材料制备方面的优势及作用,综述了其在电极材料设计与构筑方面的研究进展及相关电极材料在锂离子电池、钠离子电池和超级电容器中的应用.

液晶电解质在锂离子电池中的研究进展

液晶电解质作为新型电解质材料,具有高离子导电性、优异的力学性能和热稳定性等优点,成为近年来锂离子电池领域研究的热点之一。液晶电解质可以通过自组装形成柱状相、近晶相或双连续立方相等结构,为锂离子的传输提供高效的离子传输通道。综述了液晶电解质在锂离子电池中的应用及研究进展,主要包括液晶电解质的基本概念和在锂离子电池中的研究进展,主要从离子电导率、电化学稳定性和充放电循环这3个方面来叙述。最后,对液晶电解质在锂离子电池领域未来的发展进行了展望。

混合固液锂离子电池的热失控行为研究

混合固液电解质锂离子电池是一种具有高能量密度、高安全性的储能器件,有望短期内实现产业化。本工作选择混合固液电解质(LATP和电解液)匹配高比容量活性材料(正极NCM811和负极C@SiO)为研究体系,采用绝热加速量热仪和气相色谱仪对全SOC及不同全寿命周期下混合固液电解质锂离子电池进行热失控模拟和产气组分分析,并通过超声检测仪分析不同寿命周期下电解液含量的变化情况。研究结果显示:该体系新鲜电池随荷电态的增加而热安全性降低,产气量增大,且可燃气体的占比会增加。随着循环容量的衰减,电池样品的热失控起始温度、最高产热速率以及产气量变化有所差异,在容量保持率为70%时热稳定性有所改善,结合超声分析结果推测与电解液转化成固态电解质有关。该工作初步探究了该体系电池的热失控行为,为后期内部机理解析和电池设计提供了支撑。

Electric Conductivity of Fluorinated Oligomer Gel Electrolyte Including Ionic Liquid and Performance of Dye Sensitized Solar Cell

Fluorinated oligomer gel is suitable to the electrolyte of dye sensitized solar cell. This article studied mainly in the scope of electric conductivity, including ionic liquid in the electrolyte. It was found that the ratio of mixing with dimetyl sulfoxide and the concentration of LiI affect the conductivity. The behavior is different depending on the type of ionic liquid. Although the mixing ionic liquid enhances the conductivity, the short circuit current density of assembled solar cell with it was suppressed so much.