辛硫磷和氯氰菊酯的大口径毛细管气相色谱定量分析研究

 对辛硫磷和氯氰菊酯的复配农药——２０％辛氯乳油进行了气相色谱定量分析的研究。以甲基对硫磷为内标,使用大口径毛细管柱,采用快速程序升温、高载气流速等手段,解决了辛硫磷高温易分解与氯氰菊酯色谱流出温度高的矛盾。在相同的色谱条件下对二者进行定量分析,变异系数分别为０．６７％和１．０％。方法简便、快速、准确。     

阿锐克乳油中氯氰菊酯的高效液相色谱分析

采用Ｈｙｐｅｒｓｉｌ硅胶柱在合适的条件下使阿锐克乳油中的氯氰菊酯的４个异构体较好分离,通过对外标法和内标法的比较,建立了氯氰菊酯快速、准确的高效液相色谱定量分析方法,该法的回收率为９９．９％～１０１．４％;标准偏差为０．００１;相对标准偏差为１．７６％。     

毛细管气相色谱,色谱—质谱联用测定金刚烷及其异构体

本文给出了金刚烷及其异构体合物系毛细管气相色谱及色谱－质谱联用分析方法，色谱柱为ＣＢＰＩ键合石英毛细管、氢火焰检则器。列出了标准曲线和检测条件，回收率为９８．３％－１０１．２％，相对标准偏差〈４．０％，本方法定量分析快速、简便、准确。     

硅胶管采样—液相色谱法测定空气中的氯氰菊酯

本文报道空气中氯氰菊酯的高效液相色谱测定方法，空气样品用硅胶管采样，经甲醇洗脱后用ＨｙｐｏｒｓｉｌＯＤＳ柱分离，紫外检测器检测，在本法的测定条件下，最低检测浓度为０．０４ｍｇ／ｍ＾３，当氯氰菊酯浓度范围为０～２５．０ｍｇ／Ｌ时，呈线性响应关系，相对标准偏差为２．４％～８．４％，本法的解吸效率为９６．８％～１００．３％，采样效率为１００％，氯氰菊酯在硅胶管中可稳定７ｄ。     

近红外光谱法同时定量测定复配乳油农药中的三种活性成分

本文采集了40个复配乳油农药的近红外光谱,用偏最小二乘回归建立并优化了辛硫磷、高效氯氰菊酯和灭多威三种活性成分的定量分析模型。最优模型结果如下:辛硫磷模型的R2、RMSEC和RMSECV分别为99.53%、0.20和0.26;高效氯氰菊酯模型的R2、RMSEC和RMSECV分别为99.83%、0.06和0.07;灭多威模型的R2、RMSEC和RMSECV分别为99.76%、0.03和0.04。对三种成分进行了外部检验,辛硫磷、高效氯氰菊酯和灭多威的外部预测误差均方根(RMSEP)分别为0.31、0.12和0.08。结果表明,近红外光谱法可以用于复配乳油农药的活性成分含量的定量分析和质量控制,预测精度可以满足实际生产需要。     

气相色谱-质谱法分析辛硫磷过程中热分解产物的研究

对辛硫磷在气相色谱分析过程中因热分解产生的分解产物进行定性与定量研究.采用气相色谱-质谱联用技术,通过质谱解析鉴定出辛硫磷的分解产物有苯甲腈、苯甲酰腈、苯乙腈和氰基苄基叉胺.研究了进样口温度、离子源温度、连接线温度等色谱与质谱条件对辛硫磷分解产物的影响,并确定氰基苄基叉胺为辛硫磷热分解的指示成分及定量分析的代表成分,从而为快速检测痕量辛硫磷提供了一种新的途径.     

戊二醛合成体系气相色谱分析

本文给出了环戊烯合成戊二醛体系的气相色谱分析方法，色谱柱为硅烷化担体载１０％ＰＥＧ－２０Ｍ固定液，氢火焰检测器，列出了标准曲线和检测条件，变异系数均〈１．５％，相对误差±２．０％以内，该定量分析快速，简便，准确。     

真空触头合金中铜碲X荧光定量分析方法研究

介绍了用滤纸薄样法对真空触头合金中常量元素铜和微量元素碲的定量分析方法。方法简便、快速、成本低、碲和铜标准偏差分析为０．０３１４和０．０６３１，相对误差分别为０．２４％和０．７３％。     

染料中间体二氰基─4─硝基苯胺的分析

应用薄层色谱（ＴＬＣ）和紫外光谱法（ＵＶ）对二氰基－４－硝基苯胺合成中涉及的主要产物进行分析。比传统化学法快速、简单、准确，回收率９９．１％～１０１．１％，相对标准偏差０．４８％～０．８５％，在０～６ｍｇ／Ｌ范围内遵守比耳定律。     

蔬菜中代碳脂肪酸及乳酸的气相色谱分析

使用４’－胆甾烯氧羰基苯并－１５－冠－５气相色谱固定相建立了蔬菜中Ｃ１－Ｃ８脂肪酸及乳酸的定性１定量分析方法，测定的线性范围为０．１０－５０ｍｇ／Ｌ，ＲＳＤ≤３．７６％，回收率≥９７．０５％，该法快速，灵敏，准确，具有实用价值。     

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.