微波消解火焰原子吸收光谱法连续测定金银花中铁、锌、铜和锰

采用微波消化技术,以氘灯背景校正方式,在HNO3介质中,直接用火焰原子吸收法在同一体系中连续测定了金银花中微量元素Fe、Zn、Cu、Mn,并优化了最佳实验条件.在选定条件下,检出限为Fe 0.0047 μg/mL,Zn 0.0032μg/mL,Cu 0.0052μg/mL,Mn 0.0028μg/mL,相对标准偏差为1.5%～3.2%,回收率为96.4%～103.4%.适用于金银花中微量Fe、Zn、Cu、Mn的测定.     

火焰原子吸收光谱法测定红花中的Cu、Fe、Zn

采用火焰原子吸收光谱法和表面增敏的方法测定了红花中Cu、Fe、Zn的含量。实验表明,使用表面活性剂十二烷基硫酸钠(SDS),可使Zn的吸光度增感34.91%,使Cu增感37.39%,Fe增感232.10%。该法的检测限分别为Zn1.85×10-3μg/mL;Fe1.50×10-2μg/mL;Cu3.50×10-2μg/mL,加标回收率在99.37%~104.23%之间。该法灵敏度高,结果准确,可用于红花等中草药中Cu、Fe、Zn的同时测定。     

火焰原子吸收光谱法测定水仙桃中六种元素的含量

为给水仙桃中微量元素的检测提供科学方法,采用浓硝酸微波消解法处理样品,利用火焰原子吸收光谱法对水仙桃中Ca、Mg、Fe、Cu、、Mn、Zn 6种元素的含量进行了测定。结果表明,水仙桃中含有丰富的人体必需常量和微量元素,Ca、Mg、Fe、Cu、Zn、Mn的质量分数分别为2658.685、1823.331、205.051、8.662、11.165、4.205μg.g1。方法的加样回收率为96.0%～102.0%。该法操作简单、结果准确,是水仙桃中微量元素检测的理想方法。     

微波消解–FAAS测定瓜蒌皮中6种元素

建立瓜蒌皮药材中Ca,Mg,Fe,Mn,Zn,Cu微量元素的含量测定方法,测定了5个产地瓜蒌皮药材6种微量元素的含量。采用微波消解法对瓜蒌皮样品进行前处理,以火焰原子吸收光谱法测定其中6种微量元素的含量。各元素线性回归方程及相关系数良好,回收率在95.3%~104.4%之间。5个产地瓜蒌皮药材中Ca,Mg,Fe,Mn,Zn,Cu的含量分别在3 276.3~5 292.6,1 797.3~3 374.5,145.9~369.3,16.21~32.38,11.36~18.36和4.376~6.374μg/g范围之间,其中Ca含量最高,其余依次为Mg,Fe,Mn,Zn,Cu。     

火焰原子吸收法测定翼梗五味子中微量元素的含量

目的：运用火焰原子吸收光谱法测定中草药翼梗五味子藤中的 Fe、 Zn、 Mg、 Ca、 Cu 5种微量元素的含量。方法用浓 HNO3-HClO4消解样品,采用标准曲线法测定其5种金属元素含量。结果所测的样品中含有丰富的人体必需微量元素, Ca 含量尤其丰富,高达15827μg/g。方法回收率在99．7％～105．0％之间,样品相对偏差小于5％。结论该法快速简便、重复性好、准确度好,适用于同类生物样品中微量元素的测定,结果令人满意。     

火焰原子吸收光谱法测定蝴蝶藤中六种金属元素的含量

中药蝴蝶藤对溃疡性结肠炎有显著疗效,为了解其治疗作用,用原子吸收光谱法测定了蝴蝶藤中6种金属元素的含量,采用浓硝酸微波消解法处理样品,用火焰原子吸收分光光度法和石墨炉法对此样品中的金属元素Fe、Cu、Zn、Mn、Ca、Pb的含量进行了测定。结果表明,蝴蝶藤中Fe、Cu、Zn、Mn、Ca、Pb含量分别为26.732、9.762、17.164、21.576、1 923.412、0.234μg.mL-1,加样回收率为97.1%～102.7%。该法操作简单、结果准确,是蝴蝶藤中微量元素检测的理想方法。     

火焰原子吸收光谱法对中药拳参中六种无机元素含量的测定

采用浓硝酸微波消解法处理样品,利用火焰原子吸收光谱法对中药拳参中常量元素Ca、Mg及微量元素Fe、Cu、、Mn、Zn的含量进行了测定。结果表明,中药拳参中含有丰富的人体必需常量和微量元素,Ca、Mg、Fe、Cu、Zn、Mn的质量分数分别为10 662.860、1 961.242、144.557、9.778、10.166、2.314μg.g-1,各元素加样回收率在96.0%~102.0%之间。该法操作简单、结果准确,是中药拳参中无机元素检测的理想方法。     

青海高原道地药材羌活和铁棒锤微量元素含量比较研究

为研究青海高原道地药材羌活和铁棒锤的特性,采用电热板消解法处理样品,原子吸收分光光度法测定了两种药材中Ca、Mg、Cu、Zn、Fe、Mn 6种金属元素的含量。结果表明,Ca、Mg、Cu、Zn、Fe、Mn 6种微量元素含量在两种道地药材中,含量最高的是Ca,平均值分别为(55.78±12.10)mg/g和(26.48±5.79)mg/g;含量最低的元素为Cu,其值分别为(0.28±0.28)mg/g和(0.09±0.06)mg/g;其它元素含量从高到低依次为Mg,Fe,Zn,Mn。可见不同地区的羌活其微量元素的含量有明显的差异,且羌活微量元素含量也存在种间差异,细叶羌活的Ca、Mg元素含量比宽叶羌活的要低,相反,Fe,Cu,Zn 3种元素含量细叶羌活的比宽叶的要高。     

Comparison of Six Trace Elements Content in Two Genuine Medicines of Notopterygium Incisum and Aconitum pendulum in Qinghai plateau

为研究青海高原道地药材羌活和铁棒锤的特性,采用电热板消解法处理样品,原子吸收分光光度法测定了两种药材中Ca、Mg、Cu、Zn、Fe、Mn 6种金属元素的含量.结果表明,Ca、Mg、Cu、Zn、Fe、Mn 6种微量元素含量在两种道地药材中,含量最高的是Ca,平均值分别为(55.78±12.10) mg/g和(26.48±5.79) mg/g;含量最低的元素为Cu,其值分别为(0.28±0.28)mg/g和(0.09±0.06) mg/g;其它元素含量从高到低依次为Mg,Fe,Zn,Mn.可见不同地区的羌活其微量元素的含量有明显的差异,且羌活微量元素含量也存在种间差异,细叶羌活的Ca、Mg元素含量比宽叶羌活的要低,相反,Fe,Cu,Zn 3种元素含量细叶羌活的比宽叶的要高.     

猪、兔、羊、鸡肝脏中必需微量元素和脂肪酸含量的比较研究

以猪、兔、羊、鸡的肝脏为材料,利用高频电感耦合等离子体原子发射光谱仪(ICP-AES)测定了其微量元素Zn、Fe、Cu、Mn的含量,新极谱仪测定了Se的含量,气相色谱仪测定了必需脂肪酸亚油酸(C反18：2)和γ-亚麻酸(Cγ-18：3)的含量。结果表明,Fe在所测五种微量元素中含量最高,Zn其次,Se最低。四种动物肝脏中,兔肝的Zn、Fe、Se含量(鲜重)最高．分别为34．00μg/g,151．70μg/g和0.14μg/g;羊肝的Cu含量(鲜重)最高,为65．72μg/g;鸡肝的Mn含量(鲜重)最高,为1．94μg/g。此外,在所测定的两种必需脂肪酸中,兔肝的亚油酸含量(鲜重)最高,为24．08％;鸡肝中γ-亚麻酸含量最高,为1．08％。结果提示,在选用动物肝脏作为营养素源和制备保健品时,应考虑微量元素和必需脂肪酸的含量特点,有效利用其营养价值。     

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.