气相色谱-微波诱导等离子体原子发射光谱法测定土壤中的微量路易氏剂

用气相色谱－微波诱导等离子体原子发射光谱（ＧＣＭＩＰＡＥＤ）对土壤中的路易氏剂的测定方法进行了研究。用稀盐酸萃取土壤中的路易氏剂或它的降解产物２－氯乙烯亚胂酸，再与１，３－二巯基丙烷反应生成挥发性环状化合物。用甲苯萃取衍生物，在４８０１９２、１８１３９７、１８９０４２ｎｍ波长处分析检测了衍生物中的氯、硫、砷等元素的发射信号。检测限为１０ｐｇ。路易氏剂的加标回收率在７１２０％～８７８８％之间。     

染毒全血与尿样中痕量路易氏剂的气相色谱-原子发射光谱联用法检测

将气相色谱-原子发射光谱联用法应用于染毒人全血及尿样中路易氏剂及其水解产物的测定.该文基于路易氏剂的结构和毒理特性,采用其特效解毒药2,3-二巯基丙硫醇(BAL)作为衍生化试剂,结合液-液萃取对样品进行预处理和富集,以气相色谱-原子发射光谱联用法定性定量.所建立的分析方法用于染毒人全血及尿样的检测,其检出限分别为50、20 μg/L(S/N＝3),相对标准偏差小于5.4%.该方法为确证路易氏剂染毒提供了一种直接的溯源性检测方法,尤其适用于BAL治疗后生物医学样品中路易氏剂的检测.     

固相微萃取-GC-MS法测定水中的三苯胂和二苯胂酸

建立了一种同时测定水中痕量三苯胂和二苯胂酸的方法,使用巯基乙酸甲酯作为二苯胂酸测定的衍生化试剂,固相微萃取耦合气相色谱-质谱法(选择离子监测)同时测定三苯胂和二苯胂酸。优化了萃取纤维丝、萃取时间、衍生化等操作条件。同时对混合物测定的回收率、相对标准偏差和最低检测限进行了研究。方法的回收率大于95%,最低检测质量浓度分别为0.0005和0.0003 mg/L,6次测定的相对标准偏差分别为5.3%、7.6%。     

3,4-二巯基甲苯衍生化法结合SPME/GC-MS技术分析尿样中超痕量氯乙烯基胂酸

选取氯乙烯基胂酸(CVAOA)为生物标志物,建立了路易氏剂染毒尿样中超痕量CVAOA的分析方法。采用正交试验,优化了CVAOA的巯基化衍生方法,选取3,4-二巯基甲苯(DMT)作为衍生试剂,CVAOA与DMT的用量摩尔比为1∶1 000,常温衍生5 min,可达到最高的衍生效率;之后在优化的顶空-固相微萃取(HS-SPME)条件下富集纯化衍生产物CVAOA-DMT;使用气相色谱-质谱/选择离子监测模式(GC-MS/SIM)进行定性定量分析。该方法在50.0 pg/m L~500 ng/m L浓度范围内呈良好的线性(r2=0.998 5),相对标准偏差(RSD)小于10%,检出限可达7.6 pg/m L,定量下限为23 pg/m L。对低、中、高3种浓度的路易氏剂染毒尿样进行检测,回收率为97.6%~105%,RSD为4.4%~7.1%。该方法分析灵敏度高,具有良好的准确度、精密度和普及性,可被广泛推广和使用。     

固相微萃取-脉冲火焰光度法测定大气及水中的路易氏剂

建立了固相微萃取（SPME）与气相色谱/脉冲火焰光度检测器（GC／PFPD）联用测定大气和水中路易氏剂及其水解产物的方法。探讨了影响SPME萃取效率的萃取头类型、萃取时间、解吸时间等因素。优化了PFPD的条件参数、衍生化试剂及衍生条件。在优化的条件下，路易氏剂衍生产物的响应值与浓度有良好的线性关系。本方法对水中路易氏剂及其水解产物的检出限为0．1μg/L；气体中路易氏剂的检出限为10ng／m^3；水样的加标回收率为96．7％-102．1％；气体样品的加标回收率为94．9％-103．0％；RSD为2．06％。     

生物医学样品中路易氏剂代谢产物分析检测方法研究进展

综述生物医学样品中路易氏剂代谢产物分析方法的研究现状,主要总结了路易氏剂染毒生物医学样品中标志物、样品制备和仪器分析方法的研究进展。路易氏剂染毒生物标志物主要包括游离和加合代谢产物两种,分析过程主要是对选定的生物标志物进行巯基化衍生和富集纯化,之后采用气相色谱–质谱、液相色谱–质谱等仪器对目标物进行检测鉴定。     

衍生化-热解吸-气相色谱法测定空气中痕量路易氏剂

通过SKC采样泵以330 mL·min-1的速率抽吸一定时间,采集空气样品于不锈钢采样管中.样品中痕量路易氏剂(化学名为2-氯乙烯二氯胂)吸附并富集于吸附剂上.路易氏剂与3,4-二巯基甲苯的衍生化及其从吸附剂上的热解吸过程均在采样管中按选定的条件进行.应用Plack-ett-Burman设计,中心复合设计及响应曲面等方法对热解吸参数进行了优化.分别配制含有116.2 mg·L-1及1.162 g·L-1路易氏剂的空气模拟样品,按所提出的方法进行分析,测得路易氏剂的回收率依次为77.1%及99.4%.     

水中含砷毒剂的1,3-二巯基丙烷衍生化法测定

以1，2－二巯基丙烷为衍生剂，衍生水中路易氏剂等含砷化合物使其转化成挥发性较好的衍生物，继之以气相色谱－质谱法测定；从优化衍生化反应的实验条件出发，研究了衍生剂用量、温度、酸度等因素；该法应用于加标水样的分析，回收率在97％－104％之间，效果较好。     

热解吸-气相色谱-质谱联用仪检测废气中路易氏剂

建立了热解吸-气相色谱-质谱(TD-GC-MS)测定日本遗弃化学武器销毁废气中路易氏剂(L)的方法,优化了TD-GC-MS方法检测废气中L的衍生化反应条件,考察了废气中碳氢化合物和多环芳烃(PAHs)对该方法的影响,测试了该方法检测不同浓度路易氏剂的精密度和不同条件下的定量检出限。结果表明,该方法对洁净空气中和实际工况条件下路易氏剂的定量检出限分别为3.1×10~(-7)mg/m~3和1.1×10~(-5)mg/m~3(采样体积30 L)。     

衍生化气相色谱—质谱法测定水中的路易氏剂及砷酸

本文研究了用气相色谱－质谱法测定水中微量路易氏剂及砷。在酸性条件下，路易氏剂及水解产物２，３－二巯基丙醇迅速反应形成挥发性的衍生物，大大提高了测定灵敏度。用选择性离子检测定量，最小检测量为每升水中１μｇ，路易氏剂的加标回收率为９５．６２％～１０５．８８％之间，砷的加标回收率为９６．３５％～１０６．０３％之间。     

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.