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1.
本文用计算机辅助单纯形优化高效液相色谱法分离、测定了精炼植物油副产物中维生索E的各种异构体。探讨了单纯形优化法指导高效液相色谱选择分离的实验条件,并编写了实用的计算机程序。实验结果表明,本法可使比较困难的条件选择工作有章可循,从而提高工作效率。  相似文献   

2.
陆路德  杨绪杰  汪信  宋启泽  华万森 《化学学报》1991,49(10):1003-1007
本文用核磁共振法研究了位移试剂Eu(fod)3与二苯并-18-冠-6的相互作用。根据观察化学位移的数据求得了逐级平衡常数值和各纯组分的化学位移值。着重分析了OCH2质子NMR峰在[R0]/[S0]>1.3时发生分裂现象, 指出分裂原因是在R2S配合物中, 在AA'位本位的几率与BB'位配位几率不同。  相似文献   

3.
本文就气相色谱/质谱/计算机联用中的SIM法用于测定植物油及其副产物中的α-生育酚(维生素E)作了初步研究,摸索最佳的实验条件,建立了一种快速、简便的分析方法。  相似文献   

4.
本文用核磁共振法研究了位移试剂Eu(fod)3与二苯并-18-冠-6的相互作用。根据观察化学位移的数据求得了逐级平衡常数值和各纯组分的化学位移值。着重分析了OCH2质子NMR峰在[R0]/[S0]>1.3时发生分裂现象, 指出分裂原因是在R2S配合物中, 在AA'位本位的几率与BB'位配位几率不同。  相似文献   

5.
本文用核磁共振法研究了位移试剂 Eu(fod)_3与二苯并-18-冠-6的相互作用.根据观察化学位移的数据求得了逐级平衡常数值和各纯组分的化学位移值.着重分析了 OCH_2质子 NMR 峰在[R_o]/[S_]>1.3时发生分裂现象,指出分裂原因是在 R_2S 配合物中,在 AA′位配位的几率与 BB′位配位几率不同.  相似文献   

6.
建立了气相色谱-质谱(GC-MS)同时测定植物油中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚等8种维生素E的分析方法。植物油样品经甲醇超声提取、浓缩、定容,在分时段选择离子监测(SIM)模式下分离分析,采用外标法进行定量。结果表明,8种维生素E可实现基线分离;在0.01~1 mg/L范围内,所有目标物均呈良好线性关系,相关系数均大于0.99;检出限和定量限分别为0.03~0.25 mg/kg和0.10~0.83 mg/kg;在芝麻油中分别添加10、50和250 mg/kg 3个水平的8种维生素E进行加标试验,平均回收率为87.5%~107.4%,相对标准偏差(RSD)≤7.5%。所建立的方法简单、准确、可靠,且灵敏度高,可用于测定植物油中8种维生素E的含量。采用上述方法对芝麻油、大豆油、菜籽油、葵花籽油、花生油、玉米油和棕榈油等7种共75个植物油样品中维生素E的含量进行测定。结果显示,芝麻油与其他6种植物油中的8种维生素E的组成和含量均有显著差异性,因此该方法可作为芝麻油掺入其他植物油的特征鉴定指标。  相似文献   

7.
磷酸酯类阴离子表面活性剂的^31P—NMR波谱分析   总被引:2,自引:0,他引:2  
用^31P核磁共振波谱定性定量分析了烷基磷酸酯盐(1)和烷基聚氧乙烯醚磷酸酯盐(2)中各含磷组分及其含量。研究了溶液PH值、氯化钠含量、样品深度等对各组分^31P化学位移的影响。探讨了影响定量准确度的因素;找出了最佳分析条件。  相似文献   

8.
用~(31)P核磁共振波谱定性定量分析了烷基磷酸酯盐(I)和烷基聚氧乙烯醚磷酸酯盐(Ⅱ)中各含磷组分及其含量。研究了溶液pH值、氯化钠含量、样品浓度等对各组分~(31)P化学位移的影响。探讨了影响定量准确度的因素;找出了最佳分析条件。  相似文献   

9.
原油与生油岩中脱羟基维生素E的发现及意义   总被引:6,自引:0,他引:6  
本文报道了检出于中国膏盐地区原油和沉积岩样中的一类新的生物标志化合物——脱羟基维生素E。给出三个同系物的质谱棒状图,并讨论了其可能的地球化学意义。  相似文献   

10.
正相高效液相色谱法测定维生素E保留时间稳定性的提高   总被引:1,自引:0,他引:1  
维生素E有许多同系物,其中以4种生育酚异构体(即α-,β-、γ-、δ-生育酚)的活性最高,其主要的生理功能是抗氧化作用。维生素E的定量方法有分光光度法、薄层层析法、荧光法、气相色谱法和高效液相色谱(HPLC)法等,其中HPLC法因具有快速、准确、样品处理简单以及分辨率高等优点而成为维生素E测定的首选方法。HPLC法测定维生素E既可以采用正相HPLC法也可以采用反相HPLC法。从近年发表的文献看,反相HPLC法的应用比正相HPLC法更普遍一些,这是由于反相HPLC法在实际应用中具有色谱柱性能稳定、保留时间恒定和色谱柱平衡快速等优点。但反相HPLC法测定维生素时维生素E与某些亲脂性化合物反应生成部分沉淀造成色谱峰峰形明显变差。  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.
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   

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20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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