气相色谱-质谱联用法在火药剖析中的应用

采用固液萃取的方法对火药样品进行处理,用气相色谱-质谱联用法对某未知火药进行成分剖析,以选择离子质谱法进行定量。目标化合物浓度在20-50mg／L范围内与色谱峰面积呈良好的线性关系,相关系数在0．9940～0．9996之间。方法加标回收率为96．9％～104.3％,测定结果的相对标准偏差为2．4％-4．9％（n=5）.气相色谱-质谱联用法可用于火药剖析研究。     

柱色谱分离、气相色谱-质谱法定性分析F-T合成油中的含氧化合物

在柱色谱柱中填充100～200目的硅胶,以二甲亚砜为洗脱剂,将F-T合成油产物分离为烃类及有机含氧化合物两部分。采用气相色谱-质谱(GC-MS)对有机含氧化合物部分进行了分析,共鉴定出有机含氧化合物139种,并对其出峰规律进行了总结。     

气相色谱法测定汽油含氧化合物与苯

本着降低生产成本,开发仪器功能,提高工作效率,建立了双柱切换-反吹技术-气相色谱法(内标法)同时测定汽油中含氧化合物与苯。考察色谱阀的切换时间,柱温等因素对结果的影响,确定了最佳操作条件,同时对方法的精密度和重复性进行验证。结果表明,含氧化合物和苯的相对标准偏差为0.05%～0.2%,加标回收率分别为98.8%和96.7%,同时测定汽油中含氧化合物和苯方法的建立,其分析结果与石化标准方法分析结果一致。     

气相色谱法快速检测乙烯中7种含氧化合物

建立了气相色谱-氢火焰离子化检测器(GC-FID)测定乙烯中7种微量含氧化合物的方法。对色谱柱柱温、载气流速和分流比等条件进行了优化;采用外标法定量,在一定浓度范围内,7种含氧化合物的标准曲线R2均大于0.99;加标回收率在91.4%~119.1%之间,相对标准偏差均小于5.0%。实验结果表明,7种含氧化合物的检出限在0.06~0.74 mL/m3之间,样品分析周期为5 min。方法适用于乙烯中微量含氧化合物的快速检测。     

气相色谱法同时测定白酒中的特征性香气成分

采用毛细管气相色谱法同时测定白酒中特征性香气成分。色谱柱为HP—Innowax（30m×0．32mmi．d．,0．5μm）．采用间歇式升温方式,检测器为氢火焰离子化检测器（FID）。在选定的色谱条件下,不同香气成分得到较好的分离。方法回收率为95．0％～104．0％,测定结果的相对标准偏差为0．4％～4．1％（n=4）,检出限为0．05—1．5mg／L。     

离心沉淀气相色谱法测定面粉中过氧化苯甲酰含量的研究

建立了离心沉淀,气相色谱氢火焰离子化检测器测定面粉中过氧化苯甲酰含量的方法。考察了不同提取时间和采用不同工作曲线对过氧化苯甲酰测定的影响。试样在石油醚中被冰乙酸还原成苯甲酸,经HP-5（30m×0．25mm×0．25μm）毛细管气相色谱柱分离,氢火焰离子化检测器测定。方法的线性范围为0．005～0．08g／L（r=0．9992）,检出限（S／N=3）为2mg／kg。在添标水平为0．06、0．18和0．30g／kg时的平均回收率为82．70％～89．46％,相对标准偏差为3．77％～6．93％。该方法仪器设备简单,测定结果灵敏、准确,适合面粉中过氧化苯甲酰的测定。     

蓝布正挥发油化学成分的GC-MS分析

研究贵州产蓝布正（Herba Gei）挥发油的化学成分，采用水蒸气蒸馏法提取蓝布正挥发性成分，用气相色谱－质谱进行分离测定，结合计算机检索技术对分离的化合物进行鉴定，应用色谱峰面积归一化法测定各成分的相对含量；水蒸气蒸馏提取物得率是0．10％，共分离出103种成分，鉴定出40个化学成分，其主要成分为脂肪酸及其甲酯类化合物、萜烯类及其含氧衍生物等，主要有棕榈酸（13．2％）、11，14，17－二十碳三烯酸甲酯（10．4％）、亚油酸（8．6％）、石竹烯氧化物（3．9％）、丁子香酚（3．4％）和反式－植醇（3．2％）等。     

毛细管气相色谱法测定三聚氰酸三烯丙酯中丙烯醇的含量

建立了毛细管气相色谱测定三聚氰酸三烯丙酯中丙烯醇含量的方法．采用25m×0．32mm×0．25μm FFAP毛细管柱分离,氢火焰离子化检测器,内标标准曲线法（正丁醇作内标物）定量．方法简便、快速、准确,测定的相对标准偏差为0．61％～1．97％,平均回收率为97．1％～100．7％．     

茶叶中除虫菊酯农药残留快速测定法

采用丙酮浸泡、超声提取茶叶中的除虫菊酯,经石墨碳固相小柱净化萃取后,用气相色谱-电子捕获检测法直接测定茶叶中的除虫菊酯的含量。甲氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯的回收率为90．4％～110％,测定结果的RSD为3．4％～8．7％（n=5）,检出限为0．001～0．006mg／kg。     

凝胶渗透色谱-气相色谱质谱法测定：花生中6种除草剂农药残留

建立了凝胶渗透色谱一气相色谱质谱（GPC～GC=MS）法测定花生中6种除草剂（氟乐灵、异恶草酮、甲草胺、二甲戊乐灵、乙氧氟草醚、喹禾灵）农药残留的方法。样品经乙腈提取,氨基固相萃取柱和凝胶渗透色谱净化,在选择离子扫描（SIM）模式下进行气相色谱质谱法测定,外标法定量。6种除草剂浓度在0．02-1．00mg／L范围内与色谱峰面积呈良好的线性,线性相关系数为O．9949～0．9998,添加回收率为77．8％-101．6％,测定结果的相对标准偏差为4．4％～11．4％（月=5）,方法的检出限为0．1～1．3μg／kg。     

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.