Synthesis of high performance,conductive PEDOT‐coated polyester yarns by OCVD technique

Production of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl₃) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT‐coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT‐coated viscose yarns. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT‐coated viscose yarns. The variation in the conductivity of PEDOT‐coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT‐coated PET yarns compared to PEDOT‐coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT‐coated conductive polyester yarns could be used in smart clothing for medical and military applications. Copyright © 2011 John Wiley & Sons, Ltd.     

MM3 parametrization of four‐ and five‐coordinated rhenium complexes by a genetic algorithm—Which factors influence the optimization performance?

Genetic algorithms (GA) were used to solve one of the multidimensional problems in computational chemistry, the optimization of force field parameters. The correlation between the composition of the GA, its parameters (p(c), p(m)) and the quality of the results were investigated. The composition was studied for all combinations of a Simple GA/Steady State GA with a Roulette Wheel/Tournament Selector using different values each for crossover (0.5, 0.7, 0.9) and mutation rates (0.01, 0.02, 0.05, 0.10, 0.20). The results show that the performance is strongly dependent on the GA scheme, where the Simple GA/Tournament Selector yields the best results. Two new MM3 parameters were introduced for rhenium compounds with coordination number four (204) and coordination number five (205), the formal oxidation states of rhenium ranging from +V to +VII. A manifold of parameters (Re-C, N, O, S) was obtained by using a diverse set of CSD structures. The advantage of the GA vs. UFF calculations is shown by comparison of several examples. The GA optimized parameters were able to reproduce the geometrical data of the X-ray structures.     

高效液相色谱多波长定性方法研究

介绍了高效液相色谱法中除常用的保留时间和光谱图定性以外的另一方法──多波长定性分析方法。根据Beer's定律可知,同一化合物在不同波长下测得的峰面积之比为定值。利用高效波相色谱多波长同时检测的方法,比较化合物在不同波长下的峰面积大小,建立了简便的定性方法,并在禁用假氮染料测定时对18种芳香腔的定性分析中得到成功的应用。     

超高效液相色谱-串联质谱法测定海水悬浮颗粒物中的8种典型脂溶性藻毒素

海水悬浮颗粒物对海洋环境中污染物的迁移转化有着重要的影响,在海水悬浮颗粒物上富集的脂溶性藻毒素会严重的毒害海洋滤食性生物。本研究建立了海水悬浮颗粒物中8种典型脂溶性藻毒素同步测定的超高效液相色谱-串联质谱( UPLC-MS/MS)分析方法。海水悬浮颗粒物样品经甲醇超声辅助提取后,以5 mmol/L 乙酸铵水溶液和乙腈为流动相,经1.7微米C18色谱柱分离,采用电喷雾串联质谱( ESI-MS/MS)多反应监测( MRM )模式检测,外标法定量。结果表明,在最佳实验条件下,8种目标物在5 min内分离良好,加标回收率在83.8%~110.4%之间,方法具有良好的精密度(相对标准偏差( RSD)≤14.1%)和灵敏度(检出限介于2.9~103 pg/g之间),在线性范围内,相关系数(R2)均大于0.996,能满足海水悬浮颗粒物中8种典型脂溶性藻毒素同步检测的要求。采用本方法初步分析了青岛沿岸海域海水悬浮颗粒物中的脂溶性藻毒素,其中PTX2被检出,含量最高可达790 pg/g(干重)。     

Determination of 12 additives in beverages by evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets combined with liquid chromatographyEI北大核心CSCD

An analytical method for the simultaneous determination of 12 additives in beverages was developed using evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets EVA-DLLME-SFOcombined with high performance liquid chromatography HPLC. The samples were extracted twice with 70%V/Vmethanol aqueous solution and extracted by EVA-DLLME-SFO method after the combination of the extractsand finally determined by HPLC. Extraction parameterssuch as types and amounts of extractantevaporant and heating agentthe concentration of saltand the extraction time were optimized. Under the optimized conditionsthere were good relationships in the ange of 0.25-50 μµg/mL with the limits of detection of 1.5 to 13.6 mg/kg and limits of quantification of 5.2 to 45.3 mg/kg. The recoveries at three spiked levels1025 and 50 mg/kgwere 76.8% to 101.2% with the relative standard deviations of 0.11% to 4.7%. The method can be used for rapid detection of 12 additives in beverages. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

超高效液相色谱-串联质谱法快速测定沉积物中11种藻毒素

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定沉积物中11种藻毒素的方法。沉积物经冷冻干燥、粉碎过筛,用0.1 mol/L EDTA-Na4P2O7溶液涡旋超声提取,经HLB固相萃取小柱净化后,用甲醇-0.2%甲酸洗脱、浓缩并氮吹定容至1 m L。经Waters BEH C18色谱小柱,以乙腈-0.2%甲酸水溶液为流动相,梯度洗脱分离后,在电喷雾正离子模式下,以超高效液相色谱-串联质谱多级监测模式(MRM)外标法进行定性定量分析。结果表明:沉积物中11种藻毒素的检出限为1.0~5.0 ng/kg。对同一环境样品进行了0.1、1.0、4.0μg/kg不同水平的加标回收试验,平均回收率为70.3%~112.5%,相对标准偏差(RSD)为2.2%~9.3%。该方法快速、灵敏、准确,可应用于沉积物中11种藻毒素的快速监测。     

重组内切纤维素酶Fpendo5A转化三七总皂苷

从嗜热细菌基因组中克隆到1个新的纤维素酶基因,并在大肠杆菌中进行了高效可溶性表达,粗酶液经镍柱亲和层析进行分离纯化.利用快速分离液相色谱-四极杆飞行时间质谱联用仪(RRLC/Q-TOF-MS)对重组内切纤维素酶Fpendo5A转化三七总皂苷的产物结构进行了鉴定,并进一步阐明其转化机制.结果表明,该酶的最适反应温度和pH值分别为80℃和5.5.Fpendo5A能够催化三七总皂苷中的主要皂苷成分,即Ra_1,Rb_1,Rc,Rd和Rg_3的侧链糖基的水解反应,但对于不同的皂苷底物,Fpendo5A选择性催化的侧链糖基类型不同.经鉴定,Fpendo5A转化Ra_1,Rb_1,Rc,Rd和Rg_3的转化产物分别为Rb_2,GypⅩⅦ,CMC_1,F_2和Rh_2.由此可见,Fpendo5A通过水解Rb_1,Rc,Rd和Rg3的C3位的β-(1,2)糖苷键分别生成GypⅩⅦ,CMC1,F2和Rh2.在转化Ra_1时,Fpendo5A通过水解Ra_1的C20位的α-(1,4)木糖苷键生成Rb2.     

超高效液相色谱-串联质谱法检测蔬菜中除虫菊素残留

建立了蔬菜中除虫菊素的超高效液相色谱-串联质谱(UPLC-MS/MS)快速检测技术。采用乙腈提取,盐析后无需净化,直接进样分析,正离子多反应监测(MRM)模式测定。结果表明,6种除虫菊素的线性关系良好,相关系数为0.999 5~0.999 9,在0.05、0.1、0.5 mg/kg 3个加标水平下,6种物质的平均回收率为73.9%~109.3%,相对标准偏差(RSDs)为0.4%~7.7%;除虫菊素Ⅰ、除虫菊素Ⅱ的定量下限为0.01mg/kg,瓜叶菊素Ⅰ、瓜叶菊素Ⅱ、茉酮菊素Ⅰ和茉酮菊素Ⅱ的定量下限为0.05 mg/kg,定量下限均指除虫菊素总量。结果表明该方法简便、快速、灵敏度高,适用于蔬菜中除虫菊素的快速检测分析。     

直接衍生离子液体富集高效液相色谱分析水基胶中脂肪族醛酮

建立了以2,4-二硝基苯肼(DNPH)直接衍生,1-丁基-3-甲基咪唑六氟磷酸盐(［BMIM］PF6)萃取富集,高效液相色谱(HPLC)分析水基胶中痕量脂肪族醛酮的方法。分散的水基胶乳液用80 mg/L DNPH衍生化试剂(含0.44 mol/L磷酸)于40 ℃衍生18 min。取离心后的上层衍生液,加入0.5 mL ［BMIM］PF6于30 ℃萃取富集,离子液体相过滤后进行HPLC分析。采用Dionex Acclaim Explosives E2色谱柱(250 mm×4.6 mm, 5 μm),以水-乙腈为流动相在流速1.2 mL/min进行梯度洗脱,色谱柱温度为35 ℃,检测波长为365 nm。结果表明,8种脂肪族醛酮的检出限为0.022～0.221 mg/kg,定量限为0.073～0.738 mg/kg,相对标准偏差为3.5%～7.3%,回收率为84.0%～102.5%。与溶剂萃取法相比,该法具有检出限和定量限低、稳定性高、测定更准确的优势。     

纳米SrTiO3对高铁酸盐电化学性能影响研究

Two ferrates, K₂FeO₄ and BaFeO₄, had been prepared and characterized by XRD, IR and SEM. The electrochemical tests of the samples were carried out in the voltage range of 0.8～2.0 V and current density of 0.5～3.0 mA·cm^-2. The results indicated that performance of Zn-BaFeO₄ battery was superior to that of Zn-MnO₂ and Zn-K₂FeO₄ batteries. Nanometer SrTiO₃ prepared by Sol-gel methode with different ratio was added to the BaFeO₄ cathode in order to improve the discharge performance. The discharge capacity of the BaFeO₄ cathode was increased from 224 mAh·g^-1 to 246 mAh·g^-1 by addition of 5% nanometer SrTiO₃. The reason of enhancing BaFeO₄ electrochemical performance was discussed.