电喷雾质谱分析中药龙胆逆流色谱分离产物

High speed counter current chromatography was successfully applied to the preparative separation of the component of Gentiana scabra Bunge. The separation fraction was identified by ESI-MSn included Gentiopicrin and sweroside. The purity of Gentiopicrin and sweroside were over 96.5% and 74.5% via HPLC, respectively.     

用大气压电喷雾质谱快速鉴定表面活性剂

本文介绍了用大气压电喷雾质谱快速鉴定日化产品中表面活性剂的方法。表面活性剂在水溶液中离解成离子或结合水溶液中Na而带正电 ,可用大气压电喷雾质谱对其结构及组成进行鉴定 ,利用该方法亦可于 5分钟内鉴定两种或多种混合表面活性剂。     

电喷雾串联质谱监测合成帕拉米韦的反应副产物

Electrospray ionization mass spectrometry (ESI-MS) and collisional activation technology were used to determine target compound and monitor key intermediates in peramivir synthesis, a novel anti-influenza virus agent. Chemical structure of impurity formed in the last step were identified to be dehydroxylation product of peramivir based on ESI-MS and MS². Dehydroxylation product of peramivir was origined the side reaction of hydrolization of intermediate (5).     

用大气压电喷雾质谱快速鉴定阴离子表面活性剂

本文介绍了用大气压电喷雾质谱快速鉴定阴离子表面活性剂的方法。阴离子表面活性剂在水溶液中离解成负离子 ,可用大气压电喷雾质谱 (ESI- /MS)对其结构及组成进行鉴定 ,利用该方法亦可同时鉴定两种或多种混合阴离子表面活性剂     

电喷雾多级串联质谱快速鉴定木鳖子皂苷

利用电喷雾正负离子多级串联质谱相结合的方法 ,并结合皂苷部分醇解产物和皂苷元的质谱数据 ,鉴定了木鳖子皂苷的结构 ,推断了木鳖子皂苷的电喷雾质谱机理     

电喷雾质谱常见问题及处理

本文介绍Thermo的LTQ XL液相质谱联用仪,为现阶段蛋白组学中,生物分析中很常见的仪器,作者针对使用中的常见问题,给出相应的对策和处置方案,并配合一些常见的维护知识进行说明,为使用、维护和管理提供参考。     

脂肪醇聚氧乙烯醚的电喷雾质谱分析

The mass spectrum rule of the fatty alcohol polyoxyethylene ether(AEO) with different number ethoxy(EO) was discussed by electrospray ionization mass spectrometry(ESI-MS). The main peak of AEO is [M＋Na]^＋ peak, and the response value differ with number of EO. The ionization efficiency is low when the number of EO is high and low, and the ion strength is disproportionate to the concentration of sample, so the value of the number of EO detected should be revised as it is not consistent with actual number. The dimer ＋Na^＋ peak of and trimer＋Na^＋ peak will appear when the concentration of the sample injected or the intensity of the trap ion is high.     

酒黄连的电喷雾质谱研究

Using ESI-MS, adding of different weight yellow wine and different roasting temperature of prepared Coptidis Rhizoma were investigated. The results were that the influence adding of different weight yellow wine on the content of alkaloids was little, but the roasting temperature was reverse. This study offers a perspective of the technique of prepared Coptidis Rhizoma .     

甘遂炮制的电喷雾质谱研究

应用电喷雾质谱(ESI-MS)技术,根据甘遂中巨大戟二萜醇型化合物在质谱中离子强度的变化情况,采用正交实验法,优化甘遂药材醋炒和醋烘两种炮制工艺的最佳炮制条件,并提出醋烘法的炮制工艺。实验结果表明:醋炒最佳炮制条件为30%醋量,闷制24h,100℃炒25min;醋烘最佳炮制条件为30%醋量,闷制24h,110℃烘40min。     

质谱电喷雾电离源研究新进展

自1984年约翰芬恩(John Fenn)发明一种软电离离子源,即电喷雾电离源(ESI)以来,促进了质谱技术在大分子分析领域,特别是生物大分子领域的广泛使用。ESI源的低取样效率由ESI源的离子化效率和传输效率的构成,制约着ESI源质谱灵敏度的提高,因此研究者们一直努力改进ESI源的性能,以提高取样效率、改善ESI源质谱灵敏度。本研究介绍了ESI源的原理,并评述了近年来ESI源研究的新进展和应用。     

手性拆分剂的鉴别

用傅里叶变换红外光谱法,对7个没有标签的手性拆分剂进行了结构鉴定,用旋光法测定了比旋光度。结果表明,傅里叶变换红外光谱法结合旋光法可以直观、快速、准确地鉴别手性拆分剂的结构和旋光性。     

The Adsorption and Reaction of Decomposition Products of Zinc Di-Isopropyldiophosphate on Steel

Rates of adsorption and desorption, of di-isopropyldithiophosphoric acid and tetraisopropylthioperoxydiphosphate from hexade-cane on to steel, have been measured wing ¹⁴C radiolabelled compounds. Concentration, temperature, and stirring dependence have been examined. The adsorption is surface controlled and the kinetics can be represented by a Langmuir model. Correlation of rate data with antiwear properties is examined.     

Tribo-Catalysis in the Synthesis Reaction of Carbon Dioxide

Palladium was rubbed against aluminum oxide in an atmosphere of carbon monoxide and oxygen. The synthesis of carbon dioxide was enhanced during the rubbing. The activation energy of this reaction was 2.49 kJ/mol. As the sliding commenced, the desorption of carbon dioxide overshot its equilibrium value before stabilizing. The overshoot correlated with the time interval between the friction tests. The desorption mechanism of carbon dioxide is discussed in terms of the NIRAM (negative-ion-radical action mechanism) approach; exoelectron emission was enhanced by the friction of palladium. The electrons reacted with the adsorbed species to make negative-ion-radicals. These radicals further reacted on the surface to form carbon dioxide, which then desorbed.     

平面运动链同构识别的标号法

平面机构运动链的同构识别是运动链再生创新设计的重要组成.文中基于平面机构运动链的结构特征,提出了解决此问题的新方法一标号法.首先对运动链各构件按一定的规则进行标号,进行规范化处理,然后用规范化缩杆邻接矩阵表示该运动链图的连接关系,根据两运动链的缩杆邻接矩阵是否相同来识别两构件是否相似.     

制冷空调产品检测主辅侧偏差及其解决方案探讨

介绍了各种制冷空调产品的性能检测过程中主辅侧偏差的测量方法,分析了影响主辅侧偏差的因素和常见主辅侧偏差的超标原因,并提出了相应的解决方法和提高的措施,旨在有利于解决当前主辅测偏差超标带来的问题。     

新显色剂NPNTT的合成及其与镉的显色反应

本文报道了1-(4-硝基苯基)-3-(4-硝基-噻唑)-三氮烯(NPNTT)的合成及其与镉的显色反应研究。在O(P聚乙二醇辛基苯基醚)的存在下,pH11.0的Na2B4O7-NaOH缓冲溶液中,该试剂能与镉发生显色反应,镉与NPNTT形成摩尔比为1:3型的配合物,在450nm处有一最大正吸收,在540nm处有一最大负吸收。以450nm为参比波长,540nm为测量波长进行双波长测定,表观摩尔吸光系数为5.23×105L/(mo·lcm),镉的浓度在0～400μg/L范围内符合比尔定律。用拟定方法测定废水中的微量镉,结果满意。     

平面运动链同构识别的距离和序列法

对平面机构运动链结构组成进行探讨后,研究了运动链中的结构不变量,并基于缩杆邻接矩阵提出了4个新的运动链结构恒量序列,这些恒量序列将杆的级别、运动副数目以及各杆的连接关系考虑在内。以此为基础,提出了对运动链进行同构识别的距离和序列法。该方法实质上是对运动链进行分类同构识别,因此具有操作简单、可靠性好、识别效率高等特点,已成功应用于12杆以下机构运动链型综合时的同构识别     

微波辅助低温固相法制备YMnO_3纳米粉体

以金属无机盐为原料,柠檬酸为络合剂,采用微波辅助低温固相法制备前驱体,再经煅烧获得YMnO3纳米粉体,研究了煅烧温度和微波功率对合成产物的影响。结果表明:通过微波辅助低温固相法可得到钇和锰原子级混合的前驱体,前驱体经800℃煅烧3h后可合成六方YMnO3相;经900℃和1 000℃煅烧后,产物中出现较多的Y2O3和YMn2O5杂质相;当煅烧温度升高为1 100℃时,可合成高纯的六方YMnO3相,但粉体的团聚现象严重;与传统低温固相法相比,采用微波辅助低温固相法经800℃煅烧后制得的YMnO3粉体分散性和球形度较好。     

管件压力矫直过程中材料性能参数在线识别

鉴于大型直缝焊管的几何特殊性,多采用压力矫直的方式修正其直线度。受材料批次、热处理、变形情况等因素的影响,焊管的性能参数会有较大波动,准确地识别出管件的材料性能参数是提高矫直精度的一个重要条件。采用有限元方法验证了相同截面形状、相同材质的小曲率曲管在压力矫直过程与直管三点弯曲过程的等价关系;依据直管三点弯曲过程的理论模型建立了在线识别材料性能参数的识别系统,只需输入管件的几何参数、矫直模具参数、载荷-行程实验数据,即可获取管件的真实材料性能参数。大型管件的有限元仿真结果和小尺寸管坯的试验结果均验证了识别系统的可行性、可靠性。