治疗冠心病中药的微量元素测定

对治疗冠心病中药丹参、降香、红花、茯苓及复方丹参注射液中铜、锌、铅、镉的含量 进行了测定。结果表明,其中必需微量元素铜、锌含量均比有害元素铅、镉的含量要高出1－2个数量级,其铜／锌比值与正常人血清铜／锌比值能较好地吻合,镉／锌比值较低。     

潮州市西湖沉积物中金属元素的污染特性研究

用原子吸收分光光度法研究了潮州市西湖沉积物中的铜、锌、铅、镉、锰、镍、镁、钙等金属元素的含量及分布规律。结果表明,铜、铅、锌、镉和镍是主要的重金属污染物,沉积物中5种重金属的平均含量为:铜584.7 mg/kg,铅149.1 mg/kg,锌360.9 mg/kg,镉1.2 mg/kg,镍76.7 mg/kg,均高于我国土壤背景值。     

高温灼烧除硫-火焰原子吸收光谱法连续测定硫精矿和硫渣中的铜、镉、铅、锌

试样在800℃的马弗炉中灼烧除硫,用王水溶解,上清液用原子吸收光谱仪于波长324.7,228.8,283.3,213.8nm处,用空气-乙炔火焰分别测量铜、镉、铅、锌的含量。方法适用于直接浸出渣中的硫渣、硫精矿中铜、铅、锌、镉含量的测定。测定范围:铜0.025%~0.50%,镉:0.025%~0.50%,铅:0.26%~5%,锌:1.0%~10.00%。     

不同年龄阶段儿童头发锌、铜、铅、镉含量比较

采用电位溶出法检测了９５３例正常儿童发锌,铜,铅,镉含量,得出深圳地区不同年龄组男,女儿童的正常参考值,同时对各元素进行了年龄组间及性别间的比较。结果显示,除发锌无显著性别差异外,男童发铜,铅,镉含量显著高于女童（Ｐ〈０．０５或Ｐ〈０．０１）,随着年龄的增长,儿童发锌含量逐渐上升,而发铜,铅,镉水平逐渐下降。     

矮小身材儿童头发微量元素分析

采用电位溶出法检测了４２例矮小身材儿童的头发锌,铜,铅,镉含量,结果显示大多数患儿发锌含量低于正常儿童,１／３患儿发铜含量减少,仅４例发铜值增高;发铅含量高于正常者３例,占７．１４％,所有患儿发镉含量均在正常范围内。     

微波消解样品-石墨炉原子吸收光谱法测定双黄连口服液及其药材中重金属元素

双黄连口服液及其中药材金银花、连翘和黄芩苷样品用硝酸-过氧化氢(3+1)混合溶液浸泡过夜,微波消解。并用石墨炉原子吸收光谱法(GF-AAS)测定了铅、镉、铬、铜、铁和锌的含量。磷酸二氢铵、8-羟基喹啉和硒(Ⅱ)分别被用作测定铅,镉,铜和铁、铬以及锌的基体改进剂。在优化的试验条件下,方法的回收率在90.4%～106.0%之间,相对标准偏差(n=5)在1.8%～4.6%之间。试验结果表明,双黄连口服液及其中药材中铁、锌、铜的含量较为丰富,铅和镉含量低于"药用植物及制剂外经贸绿色行业标准"。     

直读光谱法测定析出锌中铅、铜、铁、镉、锡、铝的含量

研究了湿法冶炼产出的析出锌,经过冲床冲压脱模、马弗炉高温熔化、模具浇铸成型、车床切削等过程,于直读光谱仪上测定析出锌中铅、铜、铁、镉、锡、铝含量的方法.通过实验确认了仪器的工作条件、熔样器皿、熔样温度、析出锌取样位置,并对熔样铸锭后铅、铜、铁、镉、锡、铝的偏析情况进行了分析,铅最大偏差达到30％,经玻璃棒搅动后保温,铅...     

大承气颗粒剂中微量元素的溶出量分析

采用原子吸收光谱法测定了大承气颗粒剂中铅、砷、镉、 铬、铜和锌的含量及其在人工胃液和人工肠液中的溶出量。结果表明，大承气颗粒剂中微量重金属元素在人工胃液中的溶出量明显高于人工肠液中，其中铜、 锌的溶出百分率较其它元素高。     

电感耦合等离子体质谱法同时检测红枣中铅、砷、镉、汞、铜、锌和16种稀土元素

为了研究哈密、若羌和和田红枣中铅、砷、镉、汞、铜、锌和16种稀土元素的含量情况,了解红枣重金属及稀土元素摄入的风险,建立同时检测红枣中铅、砷、汞、铜、锌和16种稀土元素的方法。红枣样品用微波消解法进行样品前处理,以电感耦合等离子体质谱法测定红枣中铅、砷、镉、汞、铜、锌和16种稀土元素的含量。各元素校准曲线的相关系数均大于0.999 0,检出限为0.01~0.05μg/L。加标回收率为92.1%~105.2%,测定结果的相对标准偏差为1.2%~3.6%(n=6)。用该方法测定苹果标准物质(GBW 10019),测定值与标准值一致。该方法适用于红枣类样品中多元素污染物快速检测及风险评估,红枣样品分析结果表明铅、砷、镉、汞、铜和稀土元素在3种红枣中的含量较低,风险监测数据表明红枣中存在重金属铅、镉摄入性风险。     

原子吸收光谱法测定植物叶中微量重金属

用浓硝酸与高氯酸混酸消解植物叶,其中铜、锌及锰含量较高,可直接用火焰原子吸收光谱法测定;铅、镉及铬含量较低,用石墨炉原子吸收光谱法测定;铅和镉含量甚微,受基体及共存元素干扰严重,用标准加入法消除干扰。     

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.