石墨炉原子吸收光谱法测定全血中铅的方法改进

针对不同的石墨管测定全血中铅时，用铅标准溶液制作的标准曲线和以全血为基体制作的标准工作曲线斜率的不一致，提出以磷酸氢二铵、磷酸氢二钠和硝酸铵作基体改进剂，以全血为基体制作标准工作曲线来测定全血中铅含量的方法。试验表明，此法基本消除了全血基体对血铅测定的影响，适应各种石墨管，可快速、准确地测定全血中铅。     

ICP-AES法测定钼酸铵及多钼酸铵中14个杂质元素

提出了用浓硝酸沉淀并分离大量基体钼，ICP-AES同时测定钼酸铵中14个杂质元素的方法，考虑了钼基体、酸度、谱线干扰及背景影响等情况。在未引入其它任何试剂的情况下，用硝酸既除去了大量的钼基体，又调整了溶液的酸度，用标准加入法测定钼酸铵中的杂质元素，无需加入高纯基准试剂进行基体匹配，有效降低了分析成本，又消除了由于忽略基准物质中杂质元素的含量给分析测定带来的误差。回收率在85％～112％之间。     

ICP－MS用于Eu_2O_3标准物质中铝和锌的定值分析

报道了用电感耦合等离子体质谱法测定氧比铕标准物质中Ａｌ_２Ｏ_３和ＺｎＯ的方法。考察了谱干扰和基体影响，采用Ｒｈ为内标较好地补偿了基体铕的影响。方法简便、快速，定值准确、可靠。     

钯—硝酸镁基体改进剂石墨炉原子吸收光谱法测定六味地黄丸中锡

本实验建立了钯－硝酸镁基体改进剂石墨炉原子光谱法测定六味地黄丸中锡的方法，研究了基体改进剂的加入方式对测定的影响，方法的相对标准偏差为２．５％，回收率在９０％～１１０％之间，检出限为０．３ｎｇ／ｍＬ。本方法用于中成药中锡的测定。     

平台石墨炉原子吸收法测定高温镍基合金中砷

研究了基体改进剂，灰化，原子化温度和共存元素的干扰。采用钯作基体改进剂和匹配基体镍后，提高了灵敏度，增强了抗干扰能力。在波长１９７．２ｎｍ处，用平台石墨炉原子吸收法直接测定了高温镍基合金中砷。方法特征是为８８ｐｇ，检出限为０．２７μｇ．ｇ＾－１，相对标准偏差为３．１％－５．１％，回嵋率为８５％－１００％。     

塞曼石墨炉原子吸收光谱法直接测定血液中痕量铝

采用偏振塞曼原子吸收法，以Ｃａ作基体改进剂，注入热解涂层石墨管中，直接测定用ＯＰ溶液稀释血液样品中的痕量铝，有效地消除了血液基体的干扰，克服了铝的记忆效应，从而提高了方法的测定灵敏度、重现性和准确度。     

应用扫描电镜拉伸台测定激光熔覆层结合强度

采用扫描电镜的拉伸台测定了合金表面激光熔覆层与基体的结合强度，分析了基材预热温度对界面结合强度的影响，观察了界面裂纹的形成及扩展过程。结果表明，这种方法较为准确地测量了熔支与基体之间的结合强度。     

平台石墨炉原子吸收法直接测定全血中痕量锗

研究了基体改进及其用量，锗的灰化和原子化温度以及６种共存离子的干扰，采用锶和硝酸铵混合液作基体改进剂，锗的灵敏度高，提高了方法的选择性，样品不需消化与分离，可采用平台石墨炉法直接测定血样中的痕量锗。     

钯－硝酸镁基体改进剂石墨炉原子吸收光谱法测定六味地黄丸中锡

本实验建立了钯－硝酸镁基体改进剂石墨炉原子吸收光谱法测定六味地黄丸中锡的方法。研究了基体改进剂的加入方式对测定的影响。方法的相对标准偏差为２．５％，回收率在９０％～１１０％之间，检出限为０．３ｎｇ／ｍＬ。本方法可用于中成药中锡的测定。     

电感耦合等离子体质谱法测定高纯氧化钆中痕量稀土杂质

考察了起因于钆基体的多原子离子干扰，当基体浓度为１ｇ／Ｌ时，基体质谱对相邻低质量同位素产生严重的峰前沿干扰，基体的多原子离子也会对待测稀土杂质同位素产生严重的谱干扰。研究了Ｇａ，Ｉｎ，Ｉ，Ｃｓ和Ｔｌ内标对基体抑制效应的补偿作用，加入内标元素Ｔｌ后，基本上克服了基体效应。     

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.