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1.
一种新型的色谱法——毛细管胶束电动色谱法   总被引:6,自引:1,他引:5  
竺安  傅小芸  吕建德  郑平 《色谱》1989,7(4):193-196
本文介绍了毛细管胶束电动色谱法的原理,建立了一套电动色谱实验装置。采用十二烷基硫酸钠(SDS)胶束溶液。对电中性有机化合物进行了电动色谱试验,获得了较好的结果。并考察了实验条件如电压、SDS浓度等对分离的影响。  相似文献   

2.
石油亚砜馏分的色谱法分离   总被引:3,自引:0,他引:3  
李艳莉  古国榜 《色谱》1996,14(4):253-255
用经典硅胶柱色谱法将石油亚砜PSO分离为4个馏分,对其中的第3个馏分进行了高效制备液相色谱的分离制备。通过大量的试验,建立了较好的色谱条件:以甲醇、水混合液为流动相,以C_(18)反相柱为固定相,把PSO3分离成7个不同的馏分。对其中的两个馏分PSO3_c和PSO3_e作进一步的色谱分离和纯化后,获得较纯的亚砜馏分,用作结构分析和性能研究。  相似文献   

3.
气相色谱法快速鉴定植物油   总被引:4,自引:1,他引:3  
田文荣  余仲建 《色谱》1990,8(6):393-394
分析植物油的经典方法是测定多种物理常数和进行化学分析。方法十分烦杂,费时费事,结果还不一定可靠,特别是鉴别伪劣品更困难。本文用气相色谱法快速鉴定国内常见的十三种植物油。试样经甲酯化后用φ2mm×1m 5%Reoplex 400柱在15min内就能很好地分离月桂酸、肉豆蔻酸、软脂酸、油酸、亚油酸、亚麻酸、花生烯酸和芥酸的甲酯。提出以脂肪酸甲酯作为保留指数的基准物,测  相似文献   

4.
建立了测定琥珀酸索利那新原料药中残留溶剂甲醇、乙醇、丙酮、叔丁醇、乙酸乙酯、正庚烷、石油醚、甲苯的气相色谱法和测定吡啶的高效液相色谱法。气相色谱法中以N,N-二甲基甲酰胺为溶剂,以TR-5毛细管柱为分离柱,采用氢火焰离子化检测器。高效液相色谱法中以AQC18色谱柱为分离柱,以50mmol·L-1磷酸氢二钠水溶液(含0.1%三乙胺,pH为7.6)-乙腈(1+1)为流动相,检测波长为254nm。9种溶剂的质量浓度在一定范围内呈线性,吡啶的检出限为0.01mg·L-1,其余8种溶剂的检出限在1.17~5.00 mg·L-1之间,加标回收率在86.3%~101%之间,相对标准偏差(n=6)在2.4%~6.3%之间。  相似文献   

5.
裘理仁  胡梅  李学  张银生 《色谱》1995,13(6):463-465
应用高效液相色谱法(HPLC)和凝胶色谱法(GPC)对不同合成阶段的钨酚醛树脂进行表征,以合成体系的极性和分子量的变化为依据,提出合成反应的重要控制阶段以及含钨化合物在合成反应中的行为。  相似文献   

6.
气相色谱法测定榄香烯含量   总被引:8,自引:0,他引:8  
侯丽娟  廉晓红  陈玉仁 《色谱》1996,14(5):412-413
以正己醇为内标,用气相色谱法测定榄香烯及其制剂,方法简便、快速,结果准确,可作为控制质量的方法。  相似文献   

7.
林宁 《色谱》1989,7(1):54-56
青藤碱(Sinomenine)系从防已科植物毛青藤(Sinomenium acutum Var.cinereum(Diels) Rehd)中提取的生物碱。经药理实验证实,其具有镇痛、消炎、降压、抗心律失常等作用。为了进行药物动力学研究以及临床药物监测,本实验研究了应用薄层快速分离展开血浆中青藤碱,以锯齿形和直线形薄层扫描法测定其浓度。该方法简便,快速,灵敏度较高。  相似文献   

8.
表面活性剂分子是一种两亲分子,其聚集体称为胶束,具有增溶作用。许多疏水性物质都能增溶于其非极性区。胶束的这种特殊性质,近年来被广泛应用于多种分离与分析方法中。如胶束增溶分光光度法,以及应用胶束以改进滴定分析、光谱分析和电化学分析等。本文将着重介绍胶束液相色谱法(Miccllar Liquid chromatography,MLC)。  相似文献   

9.
对薄层色谱法测定氮酮的操作条件进行了探索。选择了以丙酮为溶剂对样品进行溶解,以石油醚-异丙醚-异丙醇(体积比6:1:1)为展开剂上行展开,在碘蒸汽中显色,密封展板后进行测量。甚定性检测结果各组分分离良好,斑点集中且清晰。定量检测线性范调为15~250μg,线性方程Y(μA)=869.7514 101.9879X(μg)(n=8),相关系数为0.9986,加标回收率为101.2%,仪器精密度为1.21%,同板精密度为1.82%,均满足薄层定量分析的要求。  相似文献   

10.
杨昌金  张亿  任淑玲 《色谱》1991,9(5):324-325
茶碱(Theophylinum)化学名称为1,3-二甲基黄嘌呤,是一种用于支气管性和心脏性哮喘的常用原料药。中国药典规定的含量测定方法灵敏度低,文献报道用无水吡啶-0.05mol/L三甲基苯胺醋酸盐将茶碱衍生化后以氢火焰离子  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

14.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

15.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

16.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

17.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

18.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

19.
Siqi Li  Xingpeng Chen  Jiaxi Xu 《Tetrahedron》2018,74(14):1613-1620
Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular SN2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.  相似文献   

20.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

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