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建立了光度法测定硫普罗宁的新方法。研究表明:在SCN-和KNO3存在下,控制溶液pH4.0,Cu(II)被硫普罗宁还原生成的Cu(I)与SCN-反应形成CuSCN沉淀,该沉淀能浮在水相表面。通过测定溶液中剩余Cu(II)的量,可以测定硫普罗宁的含量。吸光度与硫普罗宁浓度之间存在良好线性关系。线性方程:A=4.898-0.3616ρ(μg/mL),线性范围为0.25~12.0μg/mL,相关系数R=0.9993,检出限为0.16μg/mL。该方法可直接用于药物中硫普罗宁含量的测定及其药代动力学行为研究。 相似文献
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硫代砷化物的合成、鉴定和定量分析方法研究 总被引:2,自引:0,他引:2
制备了4种硫代砷酸盐,采用电喷雾-高分辨质谱( ESI-HR-MS )进行鉴定,确证为一硫代砷酸盐( Hn AsSOn-33)、二硫代砷酸盐( Hn AsS2 On-32)、三硫代砷酸盐( Hn AsS3 On-3)和四硫代砷酸盐( Hn AsS4 n-3)。以合成的硫代砷酸盐为标准品,建立了基于离子色谱-电感耦合等离子质谱( IC-ICP-MS)同时测定4种硫代砷酸盐、亚砷酸盐和砷酸盐的方法。本方法线性范围为3.3~833μg/L,线性相关系数R2>0.99,方法检出限为0.4~25μg/L。本研究合成的硫代砷酸盐标准物质及建立的定量分析方法,对后续富含硫化物的天然水体中不同形态砷的迁移和转化研究具有重要意义。 相似文献
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建立了以二乙基二硫代氨基甲酸钠为配位剂,十二醇为萃取剂,乙醇为分散剂的悬浮固化分散液-液微萃取—火焰原子吸收光谱法测定水样中痕量铅的方法。详细探讨了影响萃取效率的因素。优化条件为:二乙基二硫代氨基甲酸钠的用量为10-6 mol,十二醇体积为90.00μL,乙醇体积为1.00 mL,pH为7.00。在最佳条件下,铅的检出限为1.12μg/L,富集倍率为16.00,线性范围5.00~600.00μg/L,对含有20.00μg/L和600.00μg/L Pb的标准溶液平行萃取测定11次,测定结果的RSD分别为3.73%和2.62%。本方法应用于自来水、河水及海水中痕量铅的分析,加标回收率为90.10%~100.70%。 相似文献
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非衍生化/液相色谱-串联质谱法测定食品中的二硫代氨基甲酸酯类农药残留 总被引:1,自引:0,他引:1
通过优化质谱、液相色谱和萃取缓冲液等条件,建立了一种简单、快速、灵敏测定食品中二硫代氨基甲酸酯的方法。在优化条件下,代森锌(EBDC)、丙森锌(PBDC)的线性范围为2~100μg/L,相关系数均不小于0.997。在花椰菜、萝卜和豌豆中EBDC和PBDC的检出限(S/N>3)为2μg/kg;萝卜和豌豆中EB-DC和PBDC的定量下限(S/N>10)为10μg/kg,而花椰菜中EBDC和PBDC的定量下限(S/N>10)为15μg/kg。在花椰菜、萝卜和豌豆基质中加标5~100μg/kg的EBDC和PBDC时,测定加标回收率为83%~96%,相对标准偏差为4.4%~10.5%,方法可满足定量分析的要求。 相似文献
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基于硫离子可渗透通过过氯乙烯处理滤纸,制备了硫离子选择性检测试纸。应用该试纸测定硫化物,能够有效抑制基体成分干扰,其检出限和线性范围分别为38μmol/L和50~2100μmol/L。试纸已应用于河床污泥和鱼塘沉积物中硫化物的测定。 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
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. 相似文献
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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. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
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. 相似文献
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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. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
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. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献