电感耦合等离子体原子发射光谱法测定新疆洋葱籽中常量/微量元素

采用微波消解法处理样品,以电感耦合等离子体原子发射光谱法(ICP-AES)测定新疆洋葱籽样品中Co、Cr、Ca、K、Mg、P、Fe、Mn、Na、Ni、Sn、Zn、Cd、As、Se、Cu、Mo和V 18种常量/微量元素。结果显示,新疆洋葱籽中含有丰富的K、Mg、P、Ca和Na等常量元素,此外微量元素Fe、Mn、Zn、Cr、Ni、Cu的含量也较丰富。新疆洋葱籽中含有很多对人体有益的常量及微量元素,有较高的药用价值。     

微波灰化-电感耦合等离子体原子发射光谱法测定原油中的金属元素

采用微波灰化技术消化原油样品,并使用电感耦合等离子体原子发射光谱法(ICP-AES)测定其中Na、Mg、Ca、Fe、V、Ni和Cu的含量。探讨了原油样品中金属元素测定的称样量和微波灰化程序,并优化了仪器工作参数和实验条件。样品经微波灰化处理后,用盐酸溶解残渣,方法对Na、Mg、Ca、Fe、V、Ni和Cu元素的检出限分别为0.07、0.01、0.01、0.01、0.02、0.04和0.03mg/kg,回收率在84.5%～96.6%之间,相对标准偏差在2.1%～6.9%范围。方法简便、可靠,可用于原油中Na、Mg、Ca、Fe、V、Ni和Cu 7种金属元素的检测。     

三七生长初期不同部位微量元素的含量测定

采用电感耦合等离子体发射光谱法(ICP-AES),对文山地区GAP种植及农户常规种植的生长初期三七不同部位中的微量元素Mg、P、Ca、Mn、Na、Fe、Co、Cu、Zn、Mo、Cr、Ni、Ge、Se等14种元素进行了测定分析。结果表明,三七的根、茎、叶中含有丰富的人体必需Mg、P、Ca、Mn、Na、Fe、Co、Cu、Zn、Mo、Ge、Se等有益元素,且P、Ca、Mg、Fe含量较高,Na、Mn、Co、Zn次之,Co、Mo、Cr、Ni、Ge、Se含量均较低。为三七GAP栽培标准和特征制订、三七道地药材的化学特征——化学指纹图谱的建立及研究提供理论依据。     

电感耦合等离子体质谱法(ICP-MS)同时测定正山小种红茶中18种微量元素

采用微波消解样品,应用电感耦合等离子体质谱法(ICP-MS)同时测定正山小种红茶中Na、Mg、K、Ca、Fe、Al、Zn、Mn、Cu、Ge、Cd、Cr、Ni、Se、Mo、Hg、As和Pb 18种元素。对于所测元素校准曲线的相关系数0.9990,回收率范围为90.1%～108.1%,相对标准偏差为1.54%～7.57%。正山小种红茶中Na、Mg、K、Ca、Fe、Al、Zn、Mn、Cu、Ge、Cd、Cr、Ni、Se、Mo、Hg、As和Pb 18种元素可用ICP-MS法同时测定,方法简便、快速、准确,灵敏度高。     

不同催化剂上有机质加氢热解行为及催化作用机理研究

对不同类型催化剂如Zn Cl2、Ni Cl2、Fe2O3、Y型沸石(Na Y)及Mo S2上有机质的催化加氢热解行为及反应机理进行了研究。结果表明,有机质加氢液态产物收率和组成受控于催化剂类型,但不同催化剂上加氢热解所得到的产物生标参数差异不大;同时,对于不同成熟度和类型的有机质样品,各催化剂所体现的催化效果也不尽相同。基于固体残渣元素组成、红外光谱和X射线衍射分析结果发现,不同类型催化剂上的加氢作用机制也存在明显差异。与Ni Cl2相比,Zn Cl2体系中除存在催化裂解和催化加氢作用外,还存在质量传递效应;Fe2O3催化剂主要是通过其表面的活性O吸收H2中的H形成H自由基而加速有机质的加氢反应;Mo S2体系存在过渡金属Mo的催化加氢和中间产物H2S的自由基引发作用两种催化机制。     

钨、钼、镍含量的改变对体相催化剂物化性质、加氢活性影响

制备不同活性金属原子比的体相催化剂,通过BET、XRD、SEM、TEM、强度测定、堆积密度测定及小型活性评价手段,考察了活性金属钨、钼、镍含量的变化对体相催化剂物化性质和活性的影响。结果表明,保持W/Mo原子比不变,随着(W+Mo)/Ni的原子比减小,孔体积、比表面积、孔径增大,超深度加氢脱硫活性增强,在精制油硫含量小于10μg/g,反应温度降低8℃。在(W+Mo)/Ni的原子比不变的条件下,W/Mo的原子比在0.28-1.85,随着原子比增大,孔体积、比表面积、超深度加氢脱硫活性没有明显变化。     

出生缺陷高发区人发元素含量分析研究

目的:寻找出生缺陷高发区病人体内含量异常的元素,为出生缺陷的干预和治疗提供理论依据。方法:在病区分别采集有出生缺陷儿童和健康儿童头发样品,经预处理后,采用ICP-电感耦合等离子发射光谱法,对16种元素进行了测定,所得数据采用SPSS 10.0进行非参数检验和多元回归分析。结果:与健康儿童头发样品相比,患儿发中Mo,Zn,Sr,Fe,Mg,Ca等含量显著偏低,V偏高;以病情为因变量,发中16种元素含量为自变量经逐步回归分析,有Mo,Zn,Ni等进入方程。提示该区病人体内Mo,Zn等含量低、Ni含量高与病情有关。结论:Mo,Zn等在人体内的缺乏可能是出生缺陷发生的重要因素,Sr,K,Cu,Sn,Mg,Se,Fe,Ca等含量偏低及V含量偏高可能与Mo,Zn,Ni等共同起到协同致病的作用。     

电感耦合等离子体原子发射光谱法测定紫斑牡丹胚乳和胚中矿物质元素

为了给离体体细胞胚的人工胚乳配制提供矿物质元素种类和数量方面的参考,用浓硝酸-高氯酸(4∶1)的混合溶液消解紫斑牡丹的胚乳和胚样品,采用电感耦合等离子体-原子发射光谱法(ICP-AES)测定了样品中的(K、Na、Ca、Mg、Fe、Cu、Zn、Mn、Li、Ni、B、Ag、Cd、Pb)14种矿物质元素含量。结果表明:各元素的校准曲线的回归系数在0.9990～0.9999之间,线性良好;方法精密度高,能多元素同时分析;紫斑牡丹胚乳和胚中均含有植物生长必需的K、Ca、Mg 3种大量元素,Fe、Mn、Cu、Zn、Ni、B 6种微量元素,1种有益元素Na,及Li和Pb,Ag、Cd则未被检测到。在被检测到的12种元素中,Mg、Zn、Mn、Fe、K、Na、Li与Ni 8种元素在胚乳中的含量低于胚中的含量,Ca、Cu、Pb与B在胚乳中的含量则高于胚中的含量。     

白族长寿地区硬果仁中19种元素的测定分析

用电感耦合等离子体发射光谱法（ICP－AES）,对云南省白族长寿区的葵花子仁、麻子仁和核桃仁中的Ca、Mg、P、S、Na、AI、B、Fe、Zn、Cu、Mo、Sr、Mn、Cr、Se、Ge、Cd、Pb、As等19种元素进行了测定分析。结果表明,3种硬果仁中含有丰富的人体必需的Ca、Mg、P、S、Na、Fe、Zn、Mn、Se、Cu、Cr、Sr、Mo等有益元素,且P、Mg、S、Ca、Na、Zn、Mn、Fe、Se的含量较高。这些生命元素在3种硬果仁中的含量存在差异。有害元素Cd、Pb均未检出,核桃仁中As含量较高。硬果仁中富含这些生命元素是该地区老人健康长寿的一个重要原因。     

青藏高原多年冻土区高寒草甸植物群落主要植物化学元素含量特征

分析了青藏高原北麓河地区29种高寒植物15个元素含量的特征。结果表明,这些植物中元素平均含量>400μg/g的元素有Ca,Mg,Na,K,Fe,10～100μg/g的有Mn,Cr,Zn,Cu,<10μg/g的有Ni,Co,As,Pb,Cd,Hg;种间同种元素的含量变化规律不统一。相关性分析表明,Cu与Cd,Fe与Cd和Hg,Cr与Ni,Co和Mg极显著正相关,Cr和Ca极显著负相关;聚类分析表明,Na,As元素对本区植物聚类的影响最大,莎草科、禾本科、菊科科内植物元素含量相似。     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

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.     

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.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.