首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
本文研究了水溶性试剂1-(2-吡啶偶氮)-2-萘酚-6-磺酸(PAN-S)与铁(Ⅱ)、钴(Ⅱ)和镍(Ⅱ)之螯合物的衍生和液相色谱分离条件。在Nova-PakTMC18柱上,用含10mmol/L的pH5.0的醋酸-醋酸钠缓冲溶液的甲醇-水溶液(50:50,V/V)作流动相,溴化四丁基铵(TBA·Br)作离子对试剂,流动相流速为1.0mL/min,在550nm波长处进行光度检测。在Ⅱmin内用高效液相色谱分离测定了Fe(Ⅱ)、Co(Ⅱ)和Ni(Ⅱ)与PAN—S的螯合物,提出了离子对反相高效液相色谱快速分离测定痕量铁、钴、镍的新方法。信噪比(SNR)为2时,检测下限分别为0.043、0.007和0.012mg/L。  相似文献   

2.
王瑛  刘兰珍 《分析化学》2000,28(10):1267-1270
聚酯型聚氨酯样品用基体辅助激光裂解离子化质谱(MALDI-TOF/MS)和热裂解色谱质谱(PYGC/MS)方法进行了鉴定,PYGC/MS方法可检出PU的一些组成单元的化学结构,但PYGC/MS中大多数的峰,无法从常规的标准化合物的质谱数据库中检索到,而MALDI-MS方法,可明确测出PU试样各种单元的组合、聚合度及PU长链的序列分布,质量数范围可达2300。  相似文献   

3.
通过两亲单体2-丙烯酰胺基烷磺酸与辛可宁成盐后再聚合,或AMCnS聚合成梳型两亲聚合物后再生CN成盐,可获得含辛可宁的两亲聚合物。AMCnS-CN盐及其相应的两亲聚合物具有比CN好得多的溶解性,易溶于氯仿、THF、乙醇、DMF和DMS等极性不同的溶剂。AMCsS-CN盐好得多的溶解性,易溶于氯仿、THF、乙醇、DMF和DMSO等极性不同的溶剂。AMCnS-CN盐在乙醇/氯仿(V/V=1/2)中比旋  相似文献   

4.
聚酯型聚氨酯样品用基体辅助激光裂解离子化质谱(MALDI-TOF/MS)和热裂解色谱质谱(PYGC/MS)方法进行了鉴定,PYGC/MS方法可检出PU的一些组成单元的化学结构,但PYGCIMS中大多数的峰,无法从常规的标准化合物的质谱数据库中检索到,而MALDI-MS方法,可明确测出PU试样各种单元的组合、聚合度及PU长链的序列分布,质量数范围可达2300.  相似文献   

5.
ANovelMethodofthePreparationofChemicallyModifiedElectrodesLIGen-xi,LIAOXiang-min,FANGHui-qunandCHENHong-yuan(DepartmentofChem...  相似文献   

6.
利用小分子meso-四(α,α,α,α-O-苯乙酰苯)卟啉作为全抗原免疫小鼠,通过细胞融合等技术制备了单克隆抗体(McAb)1F2,利用高效液相色谱(HPLC)、基质辅助激光解吸飞行时间质谱(MALDI/TOFMS)证明纯化得到的单抗是很纯的.McAb1F2的保留时间是2.63 min,亚型为IgG2a,相对分子量为156 678.8.McAb 1F2-卟啉复合物形成时,卟啉Soret带最大吸收峰从408nm红移到416nm,并有增色效应,说明McAb1F2-卟啉是刚性且紧密结合.抗体酶稳定性很高,但比活力只有4.687 5 U/mg,为天然酶HRP的1.899%.抗体酶的Km=20.29 mmol/L,kcat=396.82 min-1,kcat/Km=1.955 7×104L·mol-1·min-1.  相似文献   

7.
在固液相转移催化(K2CO3/DMF/TEBA)条件下,对硝基苯磺酰基乙酸酯与α、β-不饱和酸酯反应意外地生成加成重排产物。其反应机理可能是砜酯首先与α、β-不饱和酯起Michael反应,随后加成物发生分子内芳环上的新核性取代,酸化后脱去SO2得最终产物。  相似文献   

8.
柳云骐  刘晨光 《分子催化》2000,14(2):143-146
用浸渍法制备出β-A12O3负载不同Co/(Co+Mo)比的CoMo氧化物,以其作为前驱体,在N2-H2混合气体中程序升温反应,合成出一系列CoMoNx/β-A12O3催化剂催化DBT的脱硫作为模型反应,评价了催化剂的催化活性和选择性。研究表明,CoMoNx/β-A12O3催化剂催化DBT的脱硫有两条途径:一是直接氢解脱硫,产物为联苯;另一途径是DBT上的苯环先加氢然后脱硫,主要产物是环己基苯。中  相似文献   

9.
Pd(Ⅱ)、Pt(Ⅱ)DMAF配合物已合成,并已定结构。本文采用MX2(M-Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ)、Cu(Ⅱ);X=Cl,Br,I)在CH2Cl2中和DMAF作用合成[MX2.2DMAF]型配合物。由NiCl2.2DMAF.C7H8晶胞参数推知属于对称链状四配位结构。IR谱表明,该化合物化学式为MX2.2DMAF。CV表明配合物中M(Ⅱ)和Fe(Ⅱ)存在。由于金属离子互相影响。Ep/2  相似文献   

10.
系统地研究了碱性条件下(pH8~10.8)As3+,As5+,MA,DMA和AB等砷化合物在PRP-X100阴离子交换柱上的保留行为。用火焰原子吸收光谱(FAAS)测定从HPLC分离的砷化合物,即通过一根1m×0.23mmi.d.不锈钢毛细管,将HPLC柱出口与FAAS的雾化器连接起来,采用乙炔/空气火焰,在193.7nm处测定。具体研究了两个流动相(20mmol/LNH4HCO3和2.5mmol/L对-羟基苯甲酸-1.0mmol/L苯甲酸水溶液),并系统研究了pH值和缓冲液浓度对上述5个砷化合物的保留时间的影响,发现对于20mmol/LNH4HCO3体系,在pH8.7时,AB,As3+,DMA可以得到完全分离,通过梯度洗提(pH8.7到9.8,流速1.65mL/min),在15min内上述5个砷化合物可以得到良好分离;对于2.5mmol/L对-羟基苯甲酸-1.0mmol/L苯甲酸体系,在pH9.0及流速1.5mL/min时,可以在12min内将上述5个砷化合物分离。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号