阿斯美胶囊中四种组分的高效液相色谱分析

建立了反相高效液相色谱法测定阿斯美胶囊中氨茶碱、盐酸甲氧非那明、马来酸氯苯那敏及那可汀四种组分的含量。色谱柱为ＳｐｈｅｒｉｓｏｒｂＣ８，５μｍ，２００ｃｍ×４０ｍｍＩＤ，流动相为体积分数０５％的三乙胺溶液（磷酸调节ｐＨ５５）＋乙腈＋甲醇（５５０＋３６８＋８２），检测波长为２６４ｎｍ，线性范围分别为：氨茶碱３１２５～２５０ｍｇ／Ｌ，γ＝０９９９６，盐酸甲氧非那明１５６２５～１２５０ｍｇ／Ｌ，γ＝１００００，马来酸氯苯那敏２５～２００ｍｇ／Ｌ，γ＝０９９９９，那可汀８７５～７００ｍｇ／Ｌ，γ＝０９９９９；回收率（ｎ＝３）分别为１０１２％，１００８％，９９９％，９９５％；精密度：日内平均ＲＳＤ（ｎ＝６）分别为０７％，０４％，０４％，０６％；日间平均ＲＳＤ（ｎ＝３）分别为１０％，１０％，１１％，１２％。     

高效液相色谱法测定垃圾渗出液中的苯酚和对甲苯酚

介绍用气相色谱－质谱联用技术对垃圾渗出液中的酚类物质进行定性，然后用反相高效液相色谱法对苯酚和对甲苯酚进行定量分析。苯酚和对甲苯酚的线性范围分别为：５０×１０～４０×１０３ｍｇ·Ｌ－１，５０×１０２～１２×１０４ｍｇ·Ｌ－１；最低检出限为１６ｍｇ·Ｌ－１，４００ｍｇ·Ｌ－１；相对标准偏差为１１％和２９％。     

邻苯二甲醛柱前衍生反相高效液相色谱法测定人和小鼠血浆中的游离氨基酸

以邻苯二甲醛（ＯＰＡ）／３－巯基丙酸（３－ＭＰＡ）为衍生试剂，手动柱前衍生，ＯＤＳ（十八基硅烷）柱分离；以磷酸盐缓冲液（ｐＨ７２）配制流动相，二元一级线性梯度洗脱，紫外３４０ｎｍ检测，在４０ｍｉｎ内分离测定了人和小鼠血浆中２１种游离氨基酸的含量。方法准确可靠，２１种氨基酸保留时间和峰面积的相对标准偏差分别为００９％～０３８％和１５％～４９％（ｎ＝８），氨基酸的进样量为０１～１６ｎｍｏｌ时，峰面积与进样量之间的线性相关系数为０９９６～０９９９，标准加入回收率为９３３％～１０５９％。     

反相离子对色谱法测定化妆品中溴硝丙醇等11种防腐剂

采用反相离子对色谱法测定化妆品中溴硝丙醇等１１种防腐剂,以ＺｏｒｂａｘＣ８为固定相,Ｖ（０．０５ｍｏｌ／Ｌ磷酸二氢钠）∶Ｖ（甲醇）∶Ｖ（乙腈）＝５０∶３５∶１５的溶液为流动相,添加氯化十六烷三甲胺（浓度为２ｍｍｏｌ／Ｌ）,用磷酸调ｐＨ值为３５,检测波长为２５４ｎｍ。样品用甲醇超声提取,回收率为８５％～１０７％（ｎ＝６）,相对标准偏差为２２％～７．５％。     

混合苯中微量砷含量的测定

讨论了混合苯试样的消解前处理过程，提出了消解时间短、反应温和、重现性好的前处理方法。采用二乙基二硫代氨基甲酸银分光光度法测定砷含量，并与原子吸收法和砷斑法进行对照，证明方法可靠。砷含量的平均值为（１３４±００８）×１０－６，相对标准偏差为５９７％，平均回收率为（９３０±３０）％。该法最低检测限为０５μｇ，测定的线性范围为０～２５μｇ。     

土木香内酯的电化学研究

用单扫示波极谱法，在０１ｍｏｌ／ＬＬｉＣｌ中，土木香内酯有两个极谱还原波：Ｐ１（－１４１Ｖ）和Ｐ２（－１５１Ｖ）（ｖｓ．ＳＣＥ），峰Ｐ１的峰高与浓度在４３×１０－７～１２×１０－６ｍｏｌ／Ｌ和１３×１０－６～１５×１０－５ｍｏｌ／Ｌ范围内呈线性关系，可进行定量分析，用标准加入法能作定性分析，其检测限为２６×１０－７ｍｏｌ／Ｌ。测定了中药土木香中总内酯的含量，其结果令人满意。实验证明土木香内酯的电极过程为带有吸附性的不可逆的逐级电子反应过程，另外，还证明了Ｈ２Ｏ２可催化峰Ｐ１和羟基自由基可催化峰Ｐ２，讨论了土木香内酯清除由邻苯三酚自氧化产生的活性氧自由基（Ｏ－·２）的作用。     

高温钛合金中稀土相的热稳定性

对Ｔｉ５Ａｌ４Ｓｎ２Ｚｒ１Ｍｏ０．２５Ｓｉ１Ｎｄ（Ｔｉ５５）高温钛合金在α相区、α＋β相区，β相区不同温度、时间热处理样品的分析表明：在６００～９８０℃／１～１００ｈ及１０５０～１５００℃／１～１０ｈ条件下，稀土相颗粒尺寸在３３４～４２０μｍ之间波动；圆度系数在０６１９～０７５９之间波动；体积分数在１４％～１８％之间波动。稀土相颗粒尺寸、形状，体积分数基本不变，具有良好的热稳定性。     

9—冠—3衍生物载体锂离子选择性电极

报道了两种９－冠－３衍生物的合成，并以合成的化合物作载体研制了对锂离子响应的ＰＶＣ膜电极。以乙基－９－冠－３为载体的锂离子电极的能斯特响应为１０×１０－１～５２×１０－５ｍｏｌ／Ｌ，斜率为（５７４±０３）ｍＶ／ｐ［Ｌｉ］（２５℃），检测下限为２４×１０－５ｍｏｌ／Ｌ。电极具有良好的稳定性和重现性，用于实际样品测定，结果满意     

偶氮溴磺（Ⅲ）与钡配合物的分光光度研究及应用

研究了偶氮溴磺（Ⅲ）与Ｂａ２＋配合物的光度特征和显色反应的最佳条件。在较宽的ｐＨ范围内，试剂与钡形成１∶１的蓝色配合物。稳定常数Ｋ＝２３６×１０４，λｍａｘ＝６５０ｎｍ，表观摩尔吸光系数ε＝１２４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｂａ２＋浓度在６×１０－７～１×１０－４ｍｏｌ·Ｌ－１范围内遵守比耳定律。该法可满意地用于河水和自来水中Ｂａ２＋的测定。回收率在９６１％～１０１１％之间。相对标准偏差小于１５％。     

兴奋剂马钱子碱的电化学氧化及其伏安法测定

以玻碳电极为工作电极，硫酸钾为支持电解质，在合适的ｐＨ条件下，通过循环伏安法，首次观测到了马钱子碱的不可逆氧化峰。在浓度为２０×１０－４～４０×１０－３ｍｏｌ／Ｌ范围内其峰电流与浓度呈线性关系，检测限为１０×１０－５ｍｏｌ／Ｌ。在正常人体的尿样中，采用标准加入法进行回收实验，其平均回收率为１００８％。该法简便、快速，用５０×１０－４ｍｏｌ／Ｌ的马钱子碱溶液重复测定１０次，相对标准偏差为１８％。对其反应机理作了初步探讨。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

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%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.