强阳离子吸附树脂固相萃取纯化在制草乌生物碱含量测定中的应用

目的:进一步优化制草乌中二萜类生物碱成分的含量测定方法。方法:采用强阳离子吸附树脂(SCX-SPE),制备制草乌供试品溶液;采用高效液相色谱法测定,流动相为乙腈-0.2%冰醋酸溶液(三乙胺调pH至6.20),梯度洗脱,检测波长为235 nm。结果:经SCX-SPE处理,供试品色谱中新乌头碱、次乌头碱、乌头碱、苯甲酰新乌头原碱、苯甲酰次乌头原碱和苯甲酰乌头原碱等6个主要测定成分分离效果良好,平均加样回收率分别为101.16%、93.25%、99.69%、94.13%、91.79%和106.65%。9批制草乌样品中新乌头碱、次乌头碱和乌头碱3种双酯型生物碱的总量及苯甲酰新乌头原碱、苯甲酰次乌头原碱和苯甲酰乌头原碱3种单酯型生物碱的总量范围分别为0～0.0665%和0.0282%～0.5971%。结论:SCX-SPE纯化处理,可改善制草乌中二萜类生物碱的色谱峰分离情况,提高测定方法的适用性和准确度。

PPY掺杂离子对电催化脱氯Pd/PPY/Ni电极的影响

为制备高效稳定的用于电催化去除氯代有机物的电极,采用扫描电子显微镜和电催化脱氯实验考察不同聚吡咯掺杂离子对Pd/PPY/Ni复合电极的形貌和电催化加氢脱氯性能的影响.将制备的电极在强吸附性阴离子存在情况下,考察其电催化性能的变化.结果表明,掺杂离子对复合电极的形貌和电催化性能有显著的影响,对甲苯磺酸掺杂的聚吡咯对应的Pd/PPY(PTS)/Ni电极有最高的电催化加氢脱氯效率(高达91.1%),高氯酸钠掺杂的聚吡咯对应的电极电催化性能最差.电催化体系中强吸附离子(ClO4-,Cl-)的存在对电极性能有微弱影响,表明电极具有良好的稳定性,可高效去除水中的氯酚类氯代有机物.

Experimental measurements of short-term adsorption of Acidithiobacillus ferrooxidans onto chalcopyrite

The influencing factors in adsorption such as adsorption time, pulp concentration, bacterial concentration, pH as well as ionic strength were investigated to explore the relationship among them and bacterial adsorption. The adsorption was a rapid process for bacterial adhesion to chalcopyrite. The extent of adsorption increased with increasing initial bacterial concentration and pulp concentration. The optimal pH for Acidithiobacillusferrooxidans adsorption onto chalcopyrite surfaces was in the range of pH 1-3. The increase of ionic strength led to decrease in bacterial adsorption, which can be well explained by electric double layer theory. The adsorption behavior appeared to be controlled by both hydrophobic and electrostatic interactions at the interface of bacteria and mineral,

Effect of Freezing and Thawing on Ammonium Adsorption in Dryland Soil

[Objective] This study aimed to investigate the effect of freezing and thawing on ammonium adsorption in dryland soil. [Method] The lab simulation test was conducted to study the effect of freeze-thaw action on the total adsorbed amount of ammonium （deionized water extract） and strongly-adsorbed amount of ammonium （0.01 mol/L KCl solution extract） in the dryland soil of Sanjiang Plain. [Result] Compared with linear equation, Freundlich equation could better fit the total adsorbed amount of ammonium in dryland soil （R 2 0.99, SE1.69）. The freeze-thaw action almost had no influence on the total adsorbed amount of ammonium. When the initial concentration of NH 4 ＋ increased from 0 to 200 mg/L, the total adsorbed NH 4 ＋ amount increased from -0.52 to 39.0 mg/kg under freeze-thaw treatment （FTT）, while it increased from -0.70 to 38.5 mg/kg under unfreeze-thaw treatment （UFTT）. However, the strongly-adsorbed amount of ammonium presented linear relationship with the concentration of NH 4 ＋ （R 2 0.99, SE0.54）, and the strongly-adsorbed amount of ammonium increased significantly by FTT. When the initial concentration of NH 4 ＋ increased from 0 to 200 mg/L, the strongly adsorbed amount increased linearly from 2.36 to 28.81 mg/kg for FTT and from -4.25 to 25.12 mg/kg for UFTT. The freezethaw action decreases the concentration of NH 4 ＋ in soil solution when the net strongly-adsorbed NH 4 ＋ in soil is zero., therefore, FTT helped to reduce the leaching of ammonium ions in soil. Freeze-thaw action mainly influenced the exchangeable adsorbed NH 4 ＋ in soil. [Conclusion] This study provides theoretical basis for preventing excessive soil nitrogen from entering into water body and controlling water entrophication.

Thermodynamics of Cr(Ⅵ) adsorption on strong alkaline anion exchange fiber

Removal of Cr（VI） from aqueous solution by strong alkaline anion exchange fiber （SAAEF） was achieved using batch adsorption experiments. The effect of contact time, initial Cr（VI） concentration and pH was investigated. The results showed that the maximum adsorption capacity of SAAEF was 187.7 mg/g at pH=1.0. The adsorption capacity increased with Cr（VI） concentration but decreased with pH value when pH〉1.0. Adsorption isotherms at various temperatures were obtained. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models were adopted and the equilibrium data fitted best with the Langmuir isotherm. The constants of these models indicated that the adsorption process involved both chemisorption and physisorption. The values of thermodynamic parameters, including DH, DG and DS, suggested that the adsorption of Cr（VI） on SAAEF was a spontaneous, entropy-driven and endothermic process. Q（iso） was not a constant value, which indicated an inhomogenous energy distribution on SAAEF.

山楂干酒中还原性物质的分析与还原糖含量测定

用斐林试剂测定山楂酒中还原糖含量为14.2g/L,不符合干酒的还原糖要求。分析表明:半乳糖醛酸在山楂干酒中含有8.10g/L,相当于7.53g/L还原糖,多酚类物质相当于3.7g/L还原糖,是影响还原糖测定的主要还原性物质;山楂干酒中实际还原糖含量为2.97g/L,符合干酒标准。山楂干酒中的还原糖含量可以通过活性炭吸附与HPLC或活性炭与强碱性阴离子交换树脂吸附两种方法进行定量测定。

Adsorption Kineties of Pb￣(2+) and Cu￣(2+) on Variable Charge Soils andMinerals V .Effects of Temperature and Ionic Strength￣*1

The study results of the effects of temperature and ionic strength on the adsorption kineties of Pb￣2+ and Cu￣2+ bylatosol, red soil and kaolinte coated with Mn oxide showed that Pb￣2+ and Cu￣2+ adsorption by all samples, as awhole, increased with missing temperature. Temperature also increased both values of X_m (the amount of ionadsorbed at equilibrium) and k (kinetica constant) of Pb￣2+ and Cu￣2+. The activation energies of Pb￣2+ adsorption werekaolin-Mn >red soil>goethite and those of Cu￣2+ were latosol> red soil > kaolin-Mn >goethite. For a given singlesample the activation energy of Cu￣2+ was greater than that of Pb￣2+. Raising ionic strength decreased the adsorptionof Pb￣2+ and Cu￣2+ by latosol, red soil and kaolinite coated with Mn oxide but increased Pb￣2+ and Cu￣2+ adsorption bygoethite. The contrary results could be explained by the different changes in ion forms of Pb￣2+ or Cu￣2+ and in surfacecbarge characteristics of latosol, red soil, kaolin-Mn and goethite. Increasing supporting electrolyte concentration in-creased X_m and k in goethite systems but decreased X_m and k in kaolin-Mn systems. All the time-dependent data fit-ted the surface second-order equation very well.

Tunable Self-assembled Weak Polyelectrolyte Brushes

The authors have investigated the pH and ionic strength response of self-assembled layers formed by adsorption of amphiphilic weak polyelectrolytes. Using the SFA （Surface Forces Apparatus） the authors measured force-distance profiles of poly （isoprene）-poly （acrylic acid） block copolymers adsorbed on mica. Also by Atomic Force Microscopy the authors captured single polyelectrolyte molecule adsorbed on a surface. The effect of salt concentration （Cs） and pH upon the height of the brush layers was explored mainly by measuring the forces between two adsorbed polyelectrolyte brushes. At pH = 4 our results are in good agreement with the scaling prediction L0 ∝Cs-1/3 Changing the pH from 4 to 10 causes a remarkable swelling of the polymer layer, but only a weak dependence on salt concentration was detected at the higher pH. This can be attributed to the degree of dissociation, which depends on the local pH value. At low pH the polyelectrolyte chains have a low charge density, while on increasing the pH the degree of dissociation rises, and the increased charge density is followed by swelling of the adsorbed layer. The local concentration of ions in the brush is now greater than that of pH = 4 and approximately equivalent to 0.3 M. So the swelling is only weakly dependent on salt concentration in the range 0.01-1.0 M. The results demonstrate the tunable nature of such self-assembled polyelectroiyte brushes whose height and range of interactions, can be systematically controlled by adjusting the pH and ionic strength of the medium.

基于国家药品评价性抽检的制川乌质量分析及建议

目的通过国家药品评价性抽检工作,比较市场上不同厂家生产的制川乌样品的质量,分析存在的问题并提出建议,为制川乌的标准提高和市场监管提供基础数据。方法从全国28个省级行政区抽取制川乌样品,按照2015年版《中国药典》(一部)制川乌项下的性状和薄层鉴别对制川乌开展常规检验工作,出具检验报告,分析目前制川乌饮片的市场情况。针对检验中反映的情况,结合探索性研究对64家企业生产的107批制川乌质量进行评价,发现问题并开展相应检测方法研究。结果本次抽检的制川乌样品共计107批,其中3批样品性状不合格,存在用附子当做制川乌使用的情况。结论通过全国抽检发现制川乌饮片和标准中的问题,结合标准提高工作完善制川乌检验标准。

Effects of Ionic Strength and Sesquioxides on Adsorption of Toxin of Bacillus thuringiensis subsp.kurstaki on Soils

Chemical reactions and fate of the toxins of Bacillus thuringiensis （Bt） in the soil environment are causing increasing concerns due to the large-scale cultivation of transgenic Bt plants. In this study, the effect of ionic strength （0-1 000 mmol kg-1） adjusted by NaCl or CaCl2 on adsorption of Bt toxin by a lateritic red soil, a paddy soil and these soils after chemical removal of organic-bound or free Fe and Al oxides, as well as by pure minerals （goethite, hematite and gibbsite） which are widespread in these soils, were studied. The results indicated that when the supporting electrolyte was NaCl, the adsorption of Bt toxin by the lateritic red soil and paddy soil increased rapidly until the ionic strength reached 250 mmol kg-1 and then gradually slowed down with the increase of ionic strength; while in ease the supporting electrolyte was CaCl2, the adsorption of Bt toxin enhanced significantly at low ionic strength （〈 10 mmol kg-1） and then decreased as the ionic strength increased. The adsorption of Bt toxin by the tested minerals and soils after the removal of organic-bound or free Fe and Al oxides also increased with increasing ionic strength controlled by NaCl. Removing organic-bound Fe and Al oxides obviously increased the adsorption of Bt toxin in the tested soils. Differently, removing free Fe and Al oxides increased the Bt adsorption by the paddy soil, but decreased the adsorption by the lateritic red soil. The study indicated that the varieties of ionic strength and the presence of Ve and Al oxides affected the adsorption of Bt toxin by the soils, which would contribute to the further understanding of the fate of Bt toxin in the soil environment and provide references for the ecological risk assessment of transgenic Bt plants.

Investigation of radionuclide～(63)Ni(Ⅱ) sequestration mechanisms on mordenite by batch and EXAFS spectroscopy study

The sorption behavior and microscopic sequestration mechanisms of radionuclide 63Ni（II） on mordenite as a function of aging time, ionic srength, initial 63Ni（II） concentrations, solid content and coexistent electrolyte ions were investigated by the combination of batch and EXAFS techniques. Macroscopic experiment results show that the sorption of 63Ni（II） is dependent on ionic strength at pH〈7, and independent of ionic strength at pH〉7. The sorption percentage of 63Ni（II） on mordenite increases with increasing solid content, while the sorption capacity decreases as solid content increases. The presence of different electrolyte ions can enhance or inhibit the sorption of Ni（II） on mordenite in various degrees. EXAFS analysis results of the sam- ples under three different ionic strengths suggest that the retained 63Ni（II） in these samples exists in an octahedral environment with six water ligands. In the initial period of rapid uptake, the sorption of 63Ni（II） is dominated by the formation of innersphere surface complexes. As aging time increases, 63Ni（II） sequestration behavior tends to be mainly controlled by the formation of Ni phyllosilicate coprecipitates and/or Ni（OH）2（s） precipitates. Results for the second shell fit of the sample prepared at an initial 63Ni（II） concentration of 100 mg/L indicate the possible formation of Ni polynuclear surface complexes. Both the macroscopic sorption data and the molecular level evidence of 63Ni（II） surface speciation at the mordenite/water interfaces should be factored into better predictions of the mobility and bioavailability of 63Ni（II） in environment mediums.

Pyridinium salt-based covalent organic framework with well-defined nanochannels for efficient and selective capture of aqueous^(99)TcO_(4)^(-)

Ionic covalent organic framework(COF)materials with high specific surface areas and well-defined pore structures are desired for many applications yet seldom reported.Herein,we report a cationic pyridinium salt-based COF(PS-COF-1)with a Brunauer-Emmett-Teller(BET)surface area of 2703 m^(2) g^(-1),state-ofthe-art for an ionic COF.Aided by its ordered pore structure,chemical stability,and radiation resistance,PS-COF-1 showed exceptional adsorption properties toward aqueous ReO_(4)^(-)(1262 mg g^(-1))and ^(99)TcO_(4)^(-).Its adsorption performance surpassed its corresponding amorphous analogue.Importantly,PS-COF-1 exhibited fast adsorption kinetics,high adsorption capacities,and selectivity for ^(99)TcO_(4)^(-)and ReO_(4)^(-)at high ionic strengths,leading to the successful removal of ^(99)TcO_(4)^(-)under conditions relevant to low-activity waste streams at US legacy Hanford nuclear sites.In addition,PS-COF-1 can rapidly decontaminate ReO_(4)^(-)/^(99)TcO_(4)^(-)polluted potable water(~10 ppb)to drinking water level(0 ppb,part per billion)within 10 min.Density functional theory(DFT)calculations revealed PS-COF-1 has a strong affinity for ReO_(4)^(-)and ^(99)TcO_(4)^(-),thereby favoring adsorption of these low charge density anions over other common anions(e.g.,Cl^(-),NO_(3)^(-),SO_(4)^(2-),CO_(3)^(2-)).Our work demonstrates a novel cationic COF sorbent for selective radionuclide capture and legacy nuclear waste management.