单宁微球对Cr（Ⅵ）的吸附性能

利用单宁微球吸附Cr（Ⅵ）,探讨了温度、pH值、Cr（Ⅵ）初始质量浓度等因素对单宁微球吸附性能的影响,并分析了其吸附等温曲线。结果表明,单宁微球对Cr（Ⅵ）具有很好的吸附效果,吸附量可达到45.5 mg/g。单宁微球对Cr（Ⅵ）的去除率随吸附时间的延长而增大,5 h后基本达到平衡。温度对单宁微球吸附Cr（Ⅵ）的影响比较...     

Electrochemical Sensor for Ultrasensitive Determination of Doxorubicin and Methotrexate Based on Cyclodextrin‐Graphene Hybrid Nanosheets

In this work, an electrochemical sensor based on a cyclodextrin‐graphene hybrid nanosheets modified glassy carbon electrode (CD‐GNs/GCE) was proposed for the ultrasensitive determination of doxorubicin and methotrexate. The peak currents of doxorubicin and methotrexate on the CD‐GNs/GCE increased 26.5 and 23.7 fold, respectively, compared to the results obtained on the bare GCE. Under optimized conditions, the linear response ranges for doxorubicin and methotrexate are 10 nM–0.2 µM and 0.1 µM–1.0 µM, with detection limits of 0.1 nM and 20 nM, respectively. The sensor showed the advantages of simple preparation, low cost, high sensitivity, good stability and reproducibility. These properties make the prepared sensor a promising tool for the determination of trace amounts of doxorubicin and methotrexate in biological, clinical and pharmaceutical fields.     

Three New Sesquiterpene Pyridine Alkaloids from Euonymus fortunei

Three new macrocyclic β‐dihydroagarofuran‐type sesquiterpene pyridine alkaloids, fortuneines A ( 1 ), B ( 2 ), and C ( 3 ), together with the four known alkaloids wilfornine E ( 4 ), aquifoliunine E‐I ( 5 ), euoverrine B ( 6 ), and euojaponine I ( 7 ), were isolated from the aerial parts of Euonymus fortunei. Their structures were elucidated by spectroscopic methods, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and ROESY. This is the first isolation of the above sesquiterpene pyridine alkaloids from this plant, except for compound 6 .     

Selective recognition of americium by peptide-based reagents

The separation of lanthanides from minor actinides such as americium and curium is an important step during the recycling process in the treatment of nuclear waste. However, the similar chemistry and ionic size of lanthanide and actinide ions make the separation challenging. Here, we report that a peptide-based reagent can selectively bind trivalent actinides over trivalent lanthanides by means of introducing soft-donor atoms into a peptide known as a lanthanide-binding tag (LBT). Fluorescence spectroscopy has been used to measure the dissociation constant of each metal/peptide complex. A 10-fold selectivity was obtained for Am(3+) over the similarly sized lanthanide cation, Nd(3+), when the asparagine on the fifth position of a LBT was mutated to a cysteine and further functionalized by a pyridine moiety.     

Ionic liquid-enhanced photooxidation of water using the polyoxometalate anion [P2W18O62](6-) as the sensitizer

Simple polyoxometalate anions are known to be photoreduced in molecular solvents in the presence of 2-propanol or benzyl alcohol. The use of ionic liquids (ILs) as the solvent is now reported to also allow the photooxidation of water to be achieved. In particular, the photochemistry of the classic Dawson polyoxometalate salt K(6)[P(2)W(18)O(62)] has been studied in detail when water is present in the aprotic IL, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF(4)]) and the protic IL, diethanolamine hydrogen sulfate (DEAS). In these and other ILs, irradiation with white light (wavelength 275-750 nm) or UV light (wavelength 275-320 nm) leads to overall reduction of the [P(2)W(18)O(62)](6-) anion to [P(2)W(18)O(62)](7-) and concomitant oxidation of water to dioxygen and protons. The modified structure of bulk water present in ILs appears to facilitate its oxidation. Analogous results were obtained in aqueous solutions containing the protic IL as an electrolyte. The photoproducts (reduced polyoxometalate anion, dioxygen, and protons) were identified by, respectively, voltammetry, a Clark electrode, and monitoring of pH. The formal reversible potentials E(0)(F) for [P(2)W(18)O(62)](6-/7-/8-/9-/10-) couples are much more positive than in molecular solvents. The [P(2)W(18)O(62)](8-) and more reduced anions, if formed as intermediates, would efficiently reduce photoproducts H(+) or dioxygen to produce [P(2)W(18)O(62)](7-), rather than reform to [P(2)W(18)O(62)](6-). Thus, under photoirradiation conditions [P(2)W(18)O(62)](7-) acts as a kinetic sink so that in principle indirect splitting of water to produce dioxygen and dihydrogen can be achieved. The equivalent form of photooxidation does not occur in liquid water or in molecular solvents such as MeCN and MeCN/CH(2)Cl(2) containing added water, but does occur for solid K(6)[P(2)W(18)O(62)] in contact with water vapor.     

Determination of pharmaceutical and personal care products in wastewater by capillary electrophoresis with UV detection

Capillary electrophoresis (CE) offers a fast and cost-effective alternative analytical technique to LC-MS/MS for separation and quantitation of many PPCP compounds in wastewater. In this study, we have developed a method that can simultaneously analyze eight different PPCP compounds in untreated wastewater (ibuprofen, triclosan, carbamazepine, caffeine, acetaminophen, sulfamethoxazole, trimethoprim, and lincomycin), using capillary electrophoresis with UV detection (CE-UV). The method detection limit (MDL) ranged from 1.6 to 68.7 ppb through solid phase extraction. The standard limit of quantification (LOQ) ranged from 0.63 to 7.72 ppm. Factors affecting separation and quantification of PPCPs, such as pH, electrophoretic potential, buffer strength, buffer type, and additives, were investigated and optimized. Water samples from two different wastewater treatment plants were collected and analyzed. The results obtained were comparable with those of LC-MS/MS. The technique developed in this study provides a low cost, simple, fast, and relatively sensitive method for determination of various PPCPs in wastewater samples for PPCP screening.     

BiVO4膜电极的制备及其光电化学性能

以自制的BiVO4纳米粉制备膜电极, 采用电化学方法较系统地研究了退火温度和膜厚对BiVO4膜电极的光电化学行为和电子输运与复合的影响. 结果表明: 退火温度和膜厚对BiVO4膜电极的光电特性有显著的影响. 膜厚为6.75 μm时, BiVO4膜电极具有最佳的光电化学特性. 退火温度低于500 °C时, 膜电极的光电活性随着温度的升高而增强, 至500 °C时达到最大值; 此后膜电极内的体相缺陷明显增加, 导致其光电活性逐渐降低. BiVO4膜电极有良好的可见光光电转换效率, 并利用其单色光转换效率曲线计算得到BiVO4的带隙为2.36eV, 采用莫特-肖特基电化学法测得其平带电位为-0.7 V (vs Ag/AgCl). 上述结果为BiVO4光催化体系的优化提供了重要的参考.     

O,O ′-二(苯基)二硫代磷酸-N,N-二乙铵对Q235钢硫酸溶液中的缓蚀性能研究

合成了O,O′-二(苯基)二硫代磷酸-N,N-二乙铵(DEDDP),采用失重,电化学和SEM技术共同研究了DEDDP在H2SO4溶液中对Q235钢的缓蚀性能.失重法研究表明:DEDDP在H2SO4溶液中能有效地抑制Q235钢腐蚀,25C的5％H2sO4溶液中,DEDDP浓度为160 mg ·L-1时,其缓蚀率为94.6...     

Phase behavior of binary system of bromobenzene–chlorobenzene confined in SBA-15 and MCM-41

Phase behavior of binary system of bromobenzene-chlorobenzene（C6H₅Br-C₆H₅Cl） confined in SBA-15 and MCM-41（pore diameter 8 nm,3.8 nm,respectively） has been investigated by means of differential scanning calorimetry（DSC）.Phase diagram of C₆H₅Br-C₆H₅Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state,the same phase behavior as the bulk system.However,the phase diagram comprises only one boundary line,which is shifted down 22-36 K with respect to the bulk system.C₆H₅Br,C₆H₅Cl or the mixture within nanopores of MCM-41 is nonfreezing.The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.