ICP-AES 法测定中药大黄中五种微量元素

采用HNO3-H2O2体系消解大黄生药，ICP-AES法测定消解液中的五种微量元素含量。结果表明，所测定大黄中的元素含量按Mg、Fe、Mn、Zn、Cu顺序依次递减。该法测定上述元素含量的标准偏差在1．2％～5．7％之间，回收率为93．5％～99．1％。     

火焰原子吸收法测定山楂叶中钙、锰、铁、锌、镁、铜、铅、铬的含量

对广西山楂叶进行湿法消化处理,利用火焰原子吸收分光光度法测定了其中微量元素的含量。结果表明,山楂叶中含有较丰富的Ca、Mg、Fe、Mn。该法的加标回收率为99．6％～105．0％,RSD≤0．71％,测定结果准确。     

火焰原子吸收法测定夏桑菊中的10种微量元素

本文利用火焰原子吸收光谱法测定了夏桑菊冲剂中10种微量元素,研究了不同试剂及不同比例的消化液对测定结果的影响,方法回收率在98．4％～104．0％,相对标准偏差在1．5％～4．7％。结果表明,夏桑菊中对人体有益的元素Mg、Ca、Zn、Mn、Fe、Cu等含量丰富,为进一步探讨微量元素与药效的关系提供了有用的数据。     

系数倍率和卡尔曼滤波紫外分光光度法同时测定发洗剂中的苯酚、间苯二酚和水杨酸

用系数倍率和卡尔曼滤波紫外分光光度法同时测定发洗剂中苯酚、间苯二酚、水杨酸的含量，苯酚、间苯二酚、水杨酸的线性回归方程分别为：A=0．00546 0．01762X，r=0.9999；A=0．00245 0.01606X，r=0．9999；A=-0.00748 0.02491X．r=0．9999。回收率分别为97．8％～102.3％、99．9％～102．3％、99．3％～103．2％。     

火焰原子吸收光度法测定维药芜菁的微量元素

为探讨微量元素与芜菁的药效关系,用火焰原子吸收分光光度法测定了维药芜菁中的K,Na,Ca,Fe,Cu,Co,Zn,Mn,Mg等9种元素含量。结果表明,芜菁含有丰富的人体必需微量元素,其中K,Na,Ca,Zn的含量更显著;方法的回收率在93．7％～102．5％之间,RSD值在0．39％-1．3％之间,能用于维药芜菁中多种微量元素的同时测定。为芜菁的进一步研究和综合开发利用提供了新的科学依据。     

几种常见水果的微量元素分析

运用原子吸收分光光度法测定了几种常见水果中部分微量元素含量。其中榴莲的Mg、Zn、Cu、K含量位于四种水果之首。美国提子中Ca含量最高，芒果中Fe含量最高。以上差别具有统计学意义。六种元素的回收率为90％-106．5％。连续6次测定样品，变异系数(CV)为0．96％。     

多方法对比测定小儿退烧片的含量

本文经选择适当的测定波长,同时采用多波长直线回归法、P-矩阵法、系数倍率法和联立方程组新解法不经提取分离直接对比测定小儿退烧片中阿司匹林和扑热息痛的含量。这四种方法测量阿司匹林和扑热息痛的回收率和相对标准偏差分别为99．60％～100．4％,0．43％～1．74％;98．75％～100．1％,0．47％～0．98％。方法简便、快速,测定结果与药典法的结果基本一致。     

826例儿童发铅、锌、铜、铁、钙含量分析

探讨了东乡县儿童体内微量元素情况。对826例儿童发铅、锌、铜、铁、钙检测结果分各年龄组进行了分析。结果表明,826例儿童中发铅含量超标512例,占61．99％;发锌含量低标604例,占73．1％;发铜含量低标46例,占5．6％;发铁含量低标95例,占11．5％;发钙含量低标116例,占19．6％,占19．6％。5种元素含量与年龄有关,随着年龄增大,发铅、锌、铜、钙含量下降,发铁含量上升。分析表明,儿童铅污染、锌、钙缺乏程度相当普遍且严重。在儿童生长发育期进行常规的微量元素检测非常必要。     

FAAS法测定三种中药材中的微量元素

采用V（浓硝酸）＋V（高氯酸）=4＋1混酸溶解消化样品。用火焰原子吸收光谱法（FAAS）测定了红芪、黄芪、板蓝根中K、ca、Na、Mg、Fe、Mn、Zn、Cu8种微量元素的含量。结果表明,红芪中钙的含量最高,铜的含量最低;黄芪和板蓝根中镁的含量最高,铜的含量最低。各元素回收率（n=7）在96．07％～101．26％之间,RSD值（n=7）在0．60％～2．99％之间。     

高温与汗液中的微量元素

综述了人在热环境下汗液中微量元素的流失情况．汗液中流失的微量元素各家报告不一．汗Fe浓度22．5μg/L至1～3mg／L．每天汗中失Fe量为0．33～14mg．热习服后汗Fe浓度明显降低，但防化锻炼热习服后，由于出汗量显著增加，每小时汗Fe丢失量反而增加3．3%．汗Cu浓度29～1532μg／L．每天汗中失Cu量为0．3～4．7mg．热习服过程中，每天汗Cu丢失量逐渐减少，热习服后较初期可减少22％～46％，汗Zn浓度181μg／L～2．88mg／L．热体力活动时,每天汗Zn丢失量为2．16～17．24mg．热习服过程中汗Zn丢失量不减少，但防化锻炼热习服后,汗Zn浓度增高13．6％;而步兵夏季训练热习服后。汗Zn损失可减少28．4%．汗藏中其它无机元素浓度；Mn3．1～25．7、Cr2．15、Co3．15、Mo0．064、Ni13．4(2～293)、V26．6、I37．0、Sr77．9、B131、Ti17．1、A115．0、Cd1．40～2．51、Mo41～232μg/L，Ca和Mg分别为54．2和8．86mg／L．每天汗液中其它微量元素排泄量：Mn39、Co4～8、Cr1、Mo0．061、Ni20～85、I6～20、Se20、F150和Sr240～960μg．热习服后汗液中这些无机元素可减少。例如，高温越野锻炼热习服后，汗Mn浓度可降低29．9％．     

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.