高纯金属镱中杂质元素的电感耦合等离子体质谱法测定

利用电感耦合等离子体质谱仪(ICP—MS)直接测定了金属镱中除Tm、Lu外其他稀土及非稀土杂质元素;通过P507萃淋树脂色层柱,分离绝大部分Yb基体,避免了基体元素对Tm、Lu的测定干扰?定量加入内标元素Sc、Cs,有效克服了基体效应所带来的偏差。稀土杂质元素的检出限0．010～0．032μg／g,非稀土杂质元素的检出限为0.12～5．0μg／g。加标回收率为83％～105％。方法适用于纯度为99．99％～99．999％的高纯金属镱产品中杂质元素的测定。     

电感耦合等离子体质谱法测定高纯金属铋中痕量杂质元素

采用电感耦合等离子体质谱法测定了高纯金属铋中14种痕量杂质元素。考察了基体效应对测定元素的干扰影响,通过铋基体元素的分离和以Sc、In、Eu作为内标,有效克服了干扰现象。方法的检出限在0．1～4．7ng/mL;精密度在1．4％～5．0％;加标回收率在89％～114％范围。本法可满足99．999％以上金属铋中痕量杂质测定的要求。     

ICP-MS法测定超细锆钇粉中多种杂质元素的研究

用电感耦合等离子体质谱(ICP-MS)直接测定超细锆钇粉中多种杂质元素,考察了基体效应对测定元素的影响。定量加入内标元素有效地校正了基体效应及仪器波动等因素引起的测量偏差。方法的固体检出限在0．01～10／zg／g;精密度在1．1％～4．7％;加标回收率在91．0％～110．5％范围。     

感耦等离子体质谱法测定高纯氧化镥中14个痕量稀土杂质

本文报道了用感耦等离子体质谱法（ＩＣＰ－ＭＳ）测定高纯氧化镥中１４个稀土杂质的方法。镥基体对测定元素无谱线干扰，但对测定信号产生显著抑制作用。加入内标后有效地补偿了这种基体抑制效应，方法检出限为０．００５～０．０３ｎｇ／ｍＬ。样品加标为０．０１μｇ时，回收率为９０％～１０３％。精密度（ＲＳＤ）为１．４％～４．２％。方法简单，不需分离富集，样品消耗量少（１０ｍｇ）。１４个稀土元素的总测定下限（１０）可达０．５８μｇ／ｇ可直接测定纯度为９９．９％～９９．９９９９％的氧化镥中稀土杂质。     

三重串联电感耦合等离子体质谱法直接测定高纯氧化钕中14种稀土杂质元素

建立了三重串联电感耦合等离子体质谱(ICP-MS/MS)法直接测定高纯钕中的14种稀土杂质元素的方法.采用氧气和氨气反应池在串联质谱MS/MS模式,有效克服了基体对待测元素的干扰.通过优化仪器参数得到Tb,Dy和Ho的背景等效浓度分别为22,40和4 ng/L.在选定的条件下,样品加标0.5 μg/L14种混合稀土标样测得的回收率为88.6％ ～ 98.6％,使用仪器标准配置的耐高盐进样系统(HMI)测得2h信号值的相对标准偏差(RSD)为1.3％-4.1％.本方法简单实用,能够满足纯度为5N (99.999％)及以上的高纯钕中14种杂质元素的直接测定.     

ICP-MS 法测定高纯氧化铕中稀土杂质的研究

深入考察了ＩＣＰ－ＭＳ法测定高纯氧化铕时基体对稀土杂质测定的影响,研究了Ｐ５０７萃淋树脂分离大量基体Ｅｕ２Ｏ３的实验条件,建立了采用内标补偿直接测定大部分稀土杂质和经Ｐ５０７萃淋树脂分离基体后测定被干扰离子Ｔｍ相结合的高纯Ｅｕ２Ｏ３中稀土杂质的ＩＣＰ－ＭＳ分析方法。方法检出限为０．００５～０．０２１μｇ／Ｌ,加标回收率为８４％～１１２％。ＲＳＤ为１．４％～８．１％。本法适用于质量分数为９９．９９％～９９．９９９９％的高纯Ｅｕ２Ｏ３中稀土杂质的分析。     

微柱分离-ICP-MS测定高纯氧化钆中14种稀土杂质

研究了采用自制微柱分离装置分离Gd2O3基体的条件。99．9％以上基体被分离，分离周期为36min。建立了高纯Gd2O3中分离Gd后测定Yb、Lu以及内标补偿法直接测定其它12种稀土杂质的ICP—MS分析方法.定量下限为0．08～0．80μg／g，加标回收率为85％～115％，相对标准偏差为1．1％～8．5％、方法可满足快速测定99．999％ Gd2O3中14种稀土杂质的要求。     

二氧化钛中杂质元素ICP-MS法测定的研究

本文报道了用电感耦合等离子质谱（ICP-MS）测定二氧化钛中18种杂质元素的方法。样品用浓硫酸及固体硫酸铵溶解至清亮后,加入内标元素45Sc、115In、205Tl,用内标法直接测定。讨论了二氧化钛的基体效应及钛产生的质谱干扰对测定结果的影响。方法的检出限是0．03～12．0ng／mL,相对标准偏差是1．4～12．5％,加标回收率是92．0％～103％。该法具有简便、快速、灵敏、准确等优点。     

ICPMS测定高纯氧化钇中痕量稀土杂质的研究

研究了直接电感耦合等离子质谱（ＩＣＰＭＳ）测定９９．９９９％纯度氧化钇中稀土杂质的方法，详细探讨了仪器工作参数对稀土元素的测定的影响，对各种干扰现象进行了研究，并提出定量校正方法，实验表明，加入内标元素可有效地克服基体效应、接口效应和仪器工作参数漂移的影响。方法的检出限为０．００３～０．０２ｎｇ／ｍｌ，变异系数（ＣＶ％）为０．２％～５．４％，回收率为９０％～１１５％。适合９９．０％～９９．９９９％     

电感耦合等离子体质谱法测定高纯稀土样品中多种非稀土杂质

研究建立了高纯稀土样品中24种非稀土杂质元素的电感耦合等离子质谱法(ICP-MS)测定方法。考察了几类典型金属样品分析中的基体效应,引入内标元素铟,有效补偿了基体效应引起的非质谱干扰。对几种在分析过程中存在质谱干扰的样品,通过分离基体进行测定。方法测定下限为1.8~390 ng.g-1,RSD为2.9%~5.4%,加标回收率为92%~107%。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.