电感耦合等离子体质谱测定铜精矿及废料中痕量锇同位素

样品经过碱熔氧化和蒸馏分离处理,用冰浴水吸收ＯｓＯ４,电感耦合等离子体质谱（ＩＣＰ－ＭＳ）测定纳克量６种Ｏｓ同位素。方法检出限为０．００１８μｇ／Ｌ￣０．０１５μｇ／Ｌ,加标回收率为９３．８％￣１０９．７％。     

2，3－二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐。测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０～１５００μｇ／Ｌ，相对标准偏差为１．６％，加标回收率为９５％～１０６％。本法简便、快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

2,3—二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐，测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０－１５００μｇ／Ｌ相对标准偏差为１．６％，加标回收率为９５％－１０６％。本法简便，快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

单柱离子色谱法同时测定磷酸中痕量钠（Ⅰ）和铁（Ⅲ）

以酒石酸－乙二胺为淋洗液的单柱离子色谱法同时测定磷酸中痕量钠（Ⅰ）和铁（Ⅲ）。淋洗液最佳浓度为４．０ｍｍｏｌ．Ｌ￣（－１）、酒石酸／１．０ｍ　ｍｏｌ·Ｌ￣（－１）乙二胺。最低检测限为Ｎａ￣＋０．０５μｇ／ｍＬ、　Ｆｅ３＋　０．４５μｇ／ｍＬ。电导检测灵敏度为２．０μｇ／ｃｍ。线性范围Ｎａ￣＋、Ｆｅ３＋０．２～１．５×１０３μｇ／ｍＬ、２．５～１．０×１０３μｇ／ｍＬ。相对平均偏差Ｎａ￣＋为２．０３％、Ｆｅ３＋为０．８３％。平均回收率Ｎａ￣＋为９８．２６％、Ｆｅ３＋为９７．６２％。本法简便、快速、准确、选择性好。     

原子荧光光谱法测定城市污水中的铅

研究了用氢化物原子荧光法测定城市污水中铅的方法。对样品前处理方法进行了筛选,在选定的最佳实验条件下,方法检出限为０．５５μｇ／Ｌ。标样含量在２５μｇ／Ｌ时,其变异系数为０．３％。以实际样品测定,加标回收率为９６％－１０１％,变异系数在２％以内,证明本方法测定污水中的铅切实、有效。     

活性氧化铝富集火焰原子吸收法测定铬（Ⅲ）和铬（Ⅵ）

研究了内装活性氧化铝的微型柱流动注射富集分离火焰原子吸收光谱法（Ｆｌ－ＦＡＡＳ）测定水体中μｇ／Ｌ级的Ｃｒ（Ⅲ）、Ｃｒ（Ⅵ）。用０．２ｍｏｌ／Ｌ氨水将活性氧化铝转为碱式以吸附Ｃｒ（Ⅲ），１ｍｏｌ／Ｌ硝酸洗脱；用０．０１ｍｏｌ／Ｌ的硝酸将活性氧化铝转为酸式以吸附Ｃｒ（Ⅵ），０．２ｍｏｌ／Ｌ的氨水洗脱，洗脱液直接送到喷雾器中。进样３０ｓ，浓度富集２５倍。两种价态离子的校正曲线浓度范围在１～５０μｇ／Ｌ之间，检测限分别为０．６和０．７μｇ／Ｌ，样品分析速率为６０样／ｈ。研究了共存离子的干扰情况，实际水样中的加标回收率在８５％～１０５％之间。     

石墨炉原子吸收光谱法测定人血及人发中的锗

研究了人体血液及人发中锗的测试方法，其中人发样品在密封罐中消化分解，血液用Ｔｒｉｏｎ Ｘ－１００以１：８稀释，以硝酸钯和硝酸铵混合溶液作为基体改进剂，用石墨炉原子吸收光谱法进行测定，在很大程度上提高了方法的灵敏度和抗干扰能力。方法特征值为２０ｐｇ，标准检出限为０．４５μｇ／Ｌ。样品加标回收率，血液１００．９％￣１０３．２％，发样９３．７％￣９７．２％，ＲＳＤ＝５．１％。     

氢化物发生电感耦合等离子体原子发射光谱法同时测定水和生物样品中…

研究了一种小型同心氢化物发生配置一个气液分离器后与多道ＩＣＰ－ＡＥＳ联用，同时测定水和生物样品中砷、铋、锑、硒的方法。检出限为砷０．４μｇ／Ｌ，铋０．５μｇ／Ｌ，锑１．４μｇ／Ｌ，硒０．５μｇ／Ｌ，相对标准偏差为砷２．７％，铋１．５％，锑２．７％，硒１．９％。用本法测定美国和国家标准物质中的氢化元素，结果满意。     

非平衡体系中固相微萃取技术的定量分析研究：——快速监测？…

采用固相微萃取技术,以１００μｍ膜厚的聚二甲基硅氧烷纤维萃取不中１０种多环芳烃,在６０ｍｉｎ采样时间内纤维上的吸附量与采样的时间近乎成正比,分配体系达到平衡前可以定量地测定水中的待测物,该方法的线性范围在０．１￣１００μｇ／Ｌ,检出限在０．０１￣０．０３μｇ／Ｌ,１５μｇ／Ｌ的回收率在８０％￣１００％,相对标准偏差在２０％以下。     

银基汞膜电极电位溶出法测定化妆品中的铋、铅、镉

研究了一种测定化妆品中铋,铅,镉的新方法。在乙二胺－盐酸底液中以银基汞膜电极为工作电极,饱和甘汞电极为参比电极,铂电极为对电极,用电位溶出法测定化妆品中的痕量Ｂｉ,Ｐｂ,Ｃｄ。结果表明,当Ｂｉ,Ｐｂ,Ｃｄ的浓度依次在０．２５￣１８００μｇ／Ｌ,０．１￣３６００μｇ／Ｌ,０．０５￣１２００μｇ／Ｌ范围内,与峰高呈良好的线性关系,样品回收率在９７％￣１０５％之间。本法有较高的精密度和准确度,适于在化妆     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

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.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

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.