中药红毛五加化学成分的高效液相色谱/电喷雾电离/质谱/质谱(HPLC/ESI/MS2)分析

建立了中药红毛五加化学成分的HPLC/ESI/MS2定性分析方法。液相色谱条件:Zorbax SB-C18色谱柱(250 mm×4.6 mm i.d.,5 μm);乙腈-水(用冰醋酸调pH为3.0)梯度洗脱,流量0.8 mL/min;柱温30 ℃;二极管阵列检测器(DAD),检测波长254 nm。质谱条件:Agilent离子阱质谱仪;电喷雾离子(ESI)源;正离子检出模式。采用该方法得到了红毛五加的紫外(UV)色谱图、总离子流色谱图(TIC)和萃取离子色谱图(EIC),以及相应色谱峰的EIC/MS2的质谱     

高效液相色谱-四极杆飞行时间质谱分析紫甘蓝和羽衣甘蓝中花色苷

应用高效液相色谱-电喷雾/四极杆飞行时间串联质谱联用技术分析了紫甘蓝和羽衣甘蓝中的花色苷成分.选用Agilent TC-C18色谱柱(250 mm×4.6 mm×5 μm),二元线性梯度洗脱,柱后流出液采用电喷雾四极杆飞行时间质谱的正、负离子模式进行检测.根据一级质谱的分子离子和二级质谱碎片离子,获得化合物的准确分子量...     

液相色谱/质谱联用分离鉴定小肽混合物

1　实验部分　　仪器与试剂:德国BrukerEsquire3000高效液相色谱 电喷雾 离子阱多级质谱仪(HPLC ESI MS/MS);甲醇、乙腈为色谱纯,三氟乙酸(TFA)、十二烷基磺酸钠(SDS)为分析纯。色谱条件:色谱柱为MicrosorbODS柱(4 6mmi d ×250mm,5μm);检测波长,210nm;流动相为乙腈 水(含0 05%TFA,1mmol/LSDS)溶液(体积比为35∶65);流速0 4mL/min。质谱条件:ESI离子源,正离子检测模式,喷雾电压为4000V,毛细管温度为365℃,喷雾气(N2)压力为172 25kPa(25psi);干燥气(N2)流速为7L/min。2　结果与讨论2.1　小肽的合成　　采用文献[1,2]的方法,…     

高效液相色谱-质谱法分析菊芋叶中的绿原酸类化合物

建立了菊芋叶中绿原酸类化合物的高效液相色谱-紫外检测-质谱(HPLC-UV-MS)定性分析方法。液相色谱条件:Inertsil ODS-3色谱柱(250 mm×4.6 mm,5 μm);甲醇和水(含1%乙酸)梯度洗脱,流量1.0 mL/min;柱温35 ℃;检测波长327 nm。质谱条件:Thermo公司TSQ三级四极杆质谱仪;电喷雾电离(ESI)接口;负离子检出模式。采用该方法得到了菊芋叶提取物的紫外检测的色谱图、负离子监测的总离子流图以及相应色谱峰的紫外光谱图和一级、二级质谱图,对其进行解析,鉴别出菊芋叶中的7个绿原酸类成分。该方法简便、快速、灵敏度高,可以很好地对菊芋叶中的绿原酸类化合物进行定性分析。     

液相色谱-串联质谱测定面条和米粉中的硫脲

建立了米面制品中硫脲的液相色谱-串联质谱(LC-MS/MS)测定方法.实验优化了样品提取方法、液相色谱条件和质谱参数.样品用80%乙醇超声波提取,离子交换色谱分离,色谱柱为NUCLEOSIL 100-5SA 阳离子交换柱,流动相为乙腈-(1%乙酸+0.2%乙酸铵)水溶液(30: 70),流速0.5mL/min.采用电喷雾质谱正离子模式电离,多反应选择离子检测,检测离子对为m/z 77/60和m/z 77/43,其中m/z 77/60为定量离子对.结果表明: 本方法简便快速、准确可靠,相对标准偏差＜4.0%;回收率为83%～90%;检出限为0.5 mg/kg;定量下限为 5 mg/kg.     

液相色谱-串联质谱法同时测定血浆中白藜芦醇苷及其代谢产物

建立同时测定大鼠血浆中白藜芦醇苷及其代谢产物白藜芦醇的液相色谱-串联质谱方法。以Lichro-spher C18色谱柱为分析柱,乙腈-水为流动相,采用电喷雾离子源(ESI),以多反应监测(MRM)模式检测,内标法定量,用于定量分析的离子反应分别为m/z389/227(白藜芦醇苷)和m/z227/143(白藜芦醇)。血浆中的白藜芦醇苷及白藜芦醇用乙酸乙酯提取,N2吹干乙酸乙酯,残留物用甲醇溶解,注入LC/MS/MS系统进行检测。在选定的样品预处理、色谱及质谱条件下,白藜芦醇苷、白藜芦醇及内标物能够达到基线分离而且离子化效果好。用LC/MS/MS法检测大鼠血浆中的白藜芦醇苷及其代谢产物白藜芦醇,线性范围0.4~200μg/L,日内、日间精密度(RSD)均小于15%;检测血浆低、中、高3个浓度(1、20、100μg/L)白藜芦醇苷的回收率分别为106.2%、97.8%和91.6%;检测血浆低、中、高3个浓度(1、20、100μg/L)白藜芦醇的回收率分别为113.2%、103.6%和93.4%。本方法具有灵敏、准确、快速的特点,可用于白藜芦醇苷的药代动力学研究。     

白芍化学成分的UPLC/Q-TOF-MS分析

采用超高压液相色谱-飞行时间质谱(UPLC/Q-TOF-MS)在正离子、负离子模式下分析了白芍(Paeonia lactiflora Pall.)甲醇提取物中的化学成分。液相色谱分离条件为:色谱柱:Waters ACQUITYTM UPLC BEH C18(100×2.1mm,1.7μm),乙腈和0.1%甲酸水溶液梯度洗脱,体积流量为0.2 mL/min,质谱条件为:Waters ACQUITY Q-TOF-MS质谱仪,电喷雾接口,正、负离子模式检测。共推测出9个化合物的化学结构,分别为没食子酰基蔗糖,芍药苷亚硫酸酯,芍药内酯苷,芍药苷,没食子酰芍药苷及其3种同分异构体和苯甲酰芍药苷。探讨总结了芍药苷类化合物可能的裂解方式。     

高效液相色谱-质谱联用法测定纺织品中的含氯苯酚

建立了高效液相色谱-质谱联用法检测纺织品中五氯苯酚(PCP)、四氯苯酚(TeCP)。选用ZORBAX XDB-C18柱(50 mm×2.1 mm,3.5μm)为分析柱,流动相为V(甲醇)∶V(纯水)=88∶12,流速为200μL/min;质谱条件选用气动辅助电喷雾离子源(ESI),检测方式为负离子多离子反应检测(MRM);PCP、TeCP标准曲线线性范围均为0.1~100μg/L;回收率为90%~99%;相对标准偏差为3.5%~7.6%(n=5);方法检测低限为5μg/kg。方法适用于纺织品中PCP、TeCP的测定。     

六味地黄丸的高效液相色谱/电喷雾电离-质谱分析

建立了高效液相色谱/电喷雾电离-质谱定性分析六味地黄丸的方法,通过2级质谱识别了其中的9种化学成分。色谱条件为:Zorbax SB-C18色谱柱;乙腈-水二元高压梯度洗脱;二极管阵列检测器,设定波长254 nm;流速1 mL/min。质谱条件为:Agilent离子阱质谱仪;电喷雾电离(ESI)离子源;负离子检出模式。结果表明,六味地黄丸的总离子流色谱图比紫外色谱图具有更强的特征性,以质谱作为检测器是一种很好的研究中药指纹图谱的方法。     

气相色谱/质谱-选择离子检测法同时测定大米中的25种持久性有机污染物

利用超声波提取、固相萃取净化对样品进行前处理,然后采用气相色谱/质谱-选择离子检测模式对大米中的25种持久性有机污染物进行了分析。色谱条件:DB-35MS毛细管色谱柱(30 m×0.25 mm i.d.×0.25 μm);载气为氦气,流速1 mL/min;进样口温度300 ℃;不分流进样,进样量1 μL;柱温为程序升温模式。质谱条件:电子轰击电离源,70 eV;采集方式为选择离子方式,扫描质量范围50~450 u。实验采用保留时间以及定性、定量特征离子的丰度比定性,采用峰面积外标法定量,制作了25种持久性有机污染物的标准工作曲线。不同浓度水平的添加回收率试验表明,25种持久性有机污染物的添加回收率为81.99%～100.60%,相对标准偏差为2.37%～18.48%,除异狄氏剂、反式氯丹和顺式氯丹的检测限分别为20,30和20 ng/g外,其他有机污染物的检测限为0.1～5 ng/g。该方法的灵敏度、准确度和精密度均符合农药多残留测定技术的要求。     

Li2O-TiO2-SiO2-P2O5和Li2O-TiO2-Al2O3-P2O5体系锂离子固体电解质的制备及性能研究

一些具有NASICON型网格结构的固体电解质具有高的电导率和好的稳定性,NASICON的意思是Na Super Ionic Conductor[1]。当NaZr2(PO4)3中P5 被Si4 部分取代时便可以得到具有NASICON结构的Na1 xZr2SixP3-xO12体系,其具有高的钠离子电导率。然而有相同结构的Li1 xZr2SixP3-xO12体系的离子电导率却很低,这是因为Li 半径太小,而NASICON三维网格结构的离子通道太大,两者不匹配而使电导率下降[2]。但当LiZr2(PO4)3中Zr4 被离子半径小些的Ti4 取代,所得LiTi2(PO4)3的通道就与Li 半径相匹配,适合于锂离子的迁移,从而使其电导率…     

Formation of nano-crystalline quartz crystals from ZnO/MgO/Al2O3/TiO2/ZrO2/SiO2 glasses

Glasses with the compositions 50.9 SiO₂ · 20.8 Al₂O₃ · (20.8 ? x) MgO· × ZnO · 3.7 TiO₂ · 3.7 ZrO₂ with x = 0, 2.3, 4.6 and 9.3 were annealed at temperatures in the range from 850 to 1100 °C. Depending on temperature, high- or low-quartz solid solutions, magnesium aluminosilicate, mullit and spinel precipitated. These glass–ceramics exhibit excellent mechanical properties and are potential candidates for applications in micromechanics or as hard disc substrate.The larger the ZnO concentration, the lower is the glass transition temperature. Also microhardnesses and Young’s moduli increased with increasing ZnO concentration. The nucleation temperature was of minor importance. To achieve good mechanical properties, the initially formed high-quartz phase must transform to the corresponding low-quartz phase. This occurs if the quartz phase contains only minor MgO or ZnO concentrations, which can be achieved by increasing the annealing times or temperature. Then MgO, ZnO and Al₂O₃ occur as separate spinel or gahnite phase.     

Synthesis and characterization of inorganic solid electrolytes of Li2O-SiO2-P2O5 and Li2O-TiO2-SiO2-P2O5 systems

The lithium-ion-conducting inorganic solid electrolytes in the oxide systems Li₂O-SiO₂-P₂O₅ and Li₂O-TiO₂-SiO₂-P₂O₅ were prepared by the solid-state reaction, and the electrolyte pellet made by cold-pressing method had diameter of 13 mm and was about 1 mm thick. Phase identification and surface morphology of the products were carried out by X-ray diffraction and scanning electron microscopy. Ionic conductivity of the pellets was investigated through ac impedance. The results show that the adding of other cations can improve the ionic conductivity of the solid electrolyte, and the sintering temperature and duration can influence the ionic conductivity. The maximum ionic conductivity in the samples is 9.9 × 10⁻⁴ S/cm in the Li₂O-TiO₂-SiO₂-P₂O₅ system. Original Russian Text ? W. Li, M. Wang, Z.H. Li, X.F. Shang, H. Wang, Y.W. Wang, Y.B. Xu, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 11, pp. 1341–1345.     

Direct formation of cyclobutenylphosphonates from 1-alkynylphosphonates and Cp2ZrCl2/2EtMgCl/2CuCl

Zirconacycles 2 prepared from 1-alkynylphosphonates 1, zirconocene dichloride, and 2 equiv of EtMgCl are smoothly converted into cyclobutenylphosphonates 3 when treated with two equiv of CuCl in 65-81% isolated yield. The reaction is specific and general only for zirconacyclopentenyl phosphonates.     

The preparation of NbH5(Me2PCH2CH2Me2)2 and NbHL2(Me2PCH2CH2PMe2)2 (L = CO or C2H4)

MMe₅(dmpe) (M = Nb or Ta, dmpe = Me₂PCH₂CH₂PMe₂) reacts with H₂ (500 atm) and dmpe in THF at 60°C to give MH₅(dmpe)_2? NbH₅(dmpe)₂ readily reacts with two mol of CO or ethylene (L) to give NbHL₂(dmpe)₂. The exchange of the hydride ligand with the ethylene protons in NbH(C₂H₄)₂(dmpe)₂ is not rapid on the ¹H NMR time scale (60 MHz) at 95°C.     

TiO2/SiO2/CeO2复合纳米薄膜超亲水性能的研究

采用溶胶凝胶法在载玻片表面制备了均匀透明的TiO2-SiO2-CeO2超亲水性薄膜，并用X射线衍射、傅立叶红外光谱、紫外-可见分光光度计研究了SiO2及稀土铈添加对TiO2薄膜表面特征及超亲水性能的影响。结果表明，Ti02-SiO2-CeO2薄膜亲水性能及亲水持续效应显著提高。实验中掺杂的铈是以三价离子态引入的，由于Ce^3 在高温下很容易氧化，故在薄膜中铈主要以四价态形式存在。Ce^4 在光激发下很容易捕获光生电子生成Ce^3 离子，光生空穴则与表面氧离子反应形成氧空位，而氧空位对亲水性的提高具有关键作用。添加SiO2后，薄膜表面的羟基含量增加，这主要是由于TiO2与SiO2复合在表面形成Lewis酸所致。表面稳定的羟基可使亲水性在暗中保持较长时间，因而亲水持续效应提高。添加SiO2及稀土铈后，薄膜中TiO2晶粒尺寸变小，量子效应增强，这也导致亲水性提高。因此添加稀土铈及SiO2后，薄膜表面的氧空穴增多，薄膜的超亲水性及亲水持续效应提高。     

Fluorine sites in glasses and transparent glass-ceramics of the system Na2O/K2O/Al2O3/SiO2/BaF2

The transparent glass-ceramics obtained in the silicate system Na₂O/K₂O/SiO₂/BaF₂ show homogeneously dispersed BaF₂ nano crystals with a narrow size distribution. The X-ray diffraction and the nuclear magnetic resonance spectroscopy were applied to glasses and the respective glass-ceramics in order to clarify the crystallization mechanism and the role of fluorine during crystallization. With an increasing annealing time, the concentration and also the number of crystals remain approximately constant. With an increasing annealing temperature, the crystalline fraction increases until a saturation limit is reached, while the number of crystals decreases and the size of the crystals increases. Fluoride in the glassy network occurs as Al-F-Ba, Al-F-Na and also as Ba-F structures. The latter are transformed into crystalline BaF₂ and fluoride is removed from the Al-F-Ba/Na bonds. However, some fluorine is still present in the glassy phase after the crystallization.     

Formation of [Cp2TiSbMe2]2, [Cp2TiSb(SiMe3)2]2 and [Cp2TiCl]2·2Mes4Sb2

Reactions of [Cp₂Ti(btmsa)] (btmsa = bis(trimethylsilyl)acetylene) with R₄Sb₂ (R = Me, Me₃Si) give [Cp₂TiSbMe₂]₂ (1) or [Cp₂TiSb(SiMe₃)₂]₂ (2) respectively. [Cp₂TiCl]₂·2Mes₄Sb₂ (3) is serendipitously formed from [Cp₂Ti(btmsa)] and Mes₂SbH containing NH₄Cl traces.     

Removal of NO in NO/N2, NO/N2/O2, NO/CH4/N2, and NO/CH4/O2/N2 systems by flowing microwave discharges

In this paper, continuing previous work, we report on experiments carried out to investigate the removal of NO from simulated flue gas in nonthermal plasmas. The plasma-induced decomposition of small concentrations of NO in N2 used as the carrier gas and O2 and CH4 as minority components has been studied in a surface wave discharge induced with a surfatron launcher. The reaction products and efficiency have been monitored by mass spectrometry as a function of the composition of the mixture. NO is effectively decomposed into N2 and O2 even in the presence of O2, provided always that enough CH4 is also present in the mixture. Other majority products of the plasma reactions under these conditions are NH3, CO, and H2. In the absence of O2, decomposition of NO also occurs, although in that case HCN accompanies the other reaction products as a majority component. The plasma for the different reaction mixtures has been characterized by optical emission spectroscopy. Intermediate excited species of NO*, C*, CN*, NH*, and CH* have been monitored depending on the gas mixture. The type of species detected and their evolution with the gas composition are in agreement with the reaction products detected in each case. The observations by mass spectrometry and optical emission spectroscopy are in agreement with the kinetic reaction models available in literature for simple plasma reactions in simple reaction mixtures.     

Conversion of NO in NO/N2, NO/O2/N2, NO/C2H4/N2 and NO/C2H4/O2/N2 Systems by Dielectric Barrier Discharge Plasmas

An experimental study on the conversion of NO in the NO/N₂, NO/O₂/N₂, NO/C₂H₄/N₂ and NO/C₂H₄/O₂/N₂ systems has been carried out using dielectric barrier discharge (DBD) plasmas at atmospheric pressure. In the NO/N₂ system, NO decomposition to N₂ and O₂ is the dominating reaction; NO conversion to NO₂ is less significant. O₂ produced from NO decomposition was detected by an on-line mass spectrometer. With the increase of NO initial concentration, the concentration of O₂ produced decreases at 298 K, but slightly increases at 523 K. In the NO/O₂/N₂ system, NO is mainly oxidized to NO₂, but NO conversion becomes very low at 523 K and over 1.6% of O₂. In the NO/C₂H₄/N₂ system, NO is reduced to N₂ with about the same NO conversion as that in the NO/N₂ system but without NO₂ formation. In the NO/C₂H₄/O₂/N₂ system, the oxidation of NO to NO₂ is dramatically promoted. At 523 K, with the increase of the energy density, NO conversion increases rapidly first, and then almost stabilizes at 93–91% of NO conversion with 61–55% of NO₂ selectivity in the energy density range of 317–550 J L⁻¹. It finally decreases gradually at high energy density. A negligible amount of N₂O is formed in the above four systems. Of the four systems studied, NO conversion and NO₂ selectivity of the NO/C₂H₄/O₂/N₂ system are the highest, and NO/O₂/C₂H₄/N₂ system has the lowest electrical energy consumption per NO molecule converted.