硼硅酸盐矿物硼的化学分离纯化与同位素测定方法

采用碱熔法分解电气石样品,研究了3种不同纯化分离方法对硼回收和同位素测定的影响。实验表明:电气石中富含的Fe³⁺和Al³⁺对甲亚胺-H酸分光光度法测定硼含量有较大干扰,并在硼特效树脂交换分离中形成氢氧化物沉淀,阻塞交换柱;同时吸附溶液中硼元素造成回收率降低。本实验依次采用阴/阳离子混合树脂,硼特效树脂和阴/阳离子混合树脂三步离子交换进行电气石样品的纯化分离方法,实现了复杂基体中硼的完全回收（回收率99%）。在TIMS（Triton TI）采用H3和H4法拉第杯,并通过优化Zoom Optics参数（Focus Quad:15;Dispersion Quad:-85）实现静态双接收硼同位素组成测定。本方法对NIST SRM 951标准样品测定结果为¹¹B/¹⁰B=4.05044±0.00012（2σ,n=8,1μg B）,测定内外精度优于传统的动态峰跳扫。NIST SRM951测定结果为-0.3‰,表明预处理过程中无硼同位素分馏效应。天然样品硼同位素组成分别采用静态多接收PTIMS-Cs₂BO₂⁺法和MC-ICP-MS测定,数据点基本分布在1:1线上,说明MC-ICP-MS测定结果与PTIMS方法结果相一致。     

离子交换树脂去除氯化铝溶液中铁和镓工艺研究

本文采用离子交换树脂去除“一步酸溶法”提取氧化铝工艺中氯化铝溶出液的铁和镓杂质,考察了四种离子交换树脂去除杂质的能力。试验表明,D201MBP型离子交换树脂的杂质吸附率最高,最佳反应条件为树脂和溶出液质量比为1:10,反应温度70℃,反应时间30min,溶出液浓度1～1.2(原溶出液浓度设为1),Fe和Ga的吸附率可达93%和98%,且Al的损失率仅为3.9%。在室温下,用0.5%盐酸溶液洗脱饱和树脂,可达到良好的再生效果。     

Cd同位素地质样品的预处理方法研究

考察了文献报道的地质样品中Cd同位素测试前的化学分离纯化和富集方法(预处理方法)中的离子交换树脂单柱法回收率低的原因,并在该方法的基础上做了改进,优化了离子交换柱的洗涤顺序和洗液用量.改进后的离子交换树脂单柱法Cd回收率达99.82%,主要干扰元素(Sn、In、Zn、Pb)和基质元素的去除效果均较理想,能更好地满足Cd同位素的测定要求.     

珊瑚中硼的分离及其同位素组成的测定

介绍了用硼特效树脂和阴、阳混合离子交换树脂相结合进行珊瑚中硼的分离和纯化方法，满足了正热电离质谱法测定硼同位素的要求，并且对几个珊瑚样品进行了硼的分离和硼同位素组成的测定，结果满意，为研究珊瑚中的硼同位素示踪古海洋环境变化提供了可能。     

(硬)石膏矿物中硼的提取分离及硼同位素测定

(硬)石膏作为海湖水蒸发过程中常见的硫酸盐矿物,能很好反映原始母液的组成及相关水文地质信息。硼属于易溶元素,常赋存于各种蒸发岩矿物中,目前硼同位素在矿床学,地球化学,古环境等地球科学中已得到广泛应用。由于(硬)石膏硼含量较低且难溶于水和盐酸,所以其硼含量及硼同位素组成特征研究较少。本研究通过物相转化与树脂交换法提取纯化(硬)石膏中的硼:首先使用碳酸氢铵与石膏混合,将微溶硫酸钙转化为难溶碳酸钙,随后使用盐酸溶解,一次转化率为85%,两次转化与分解可以保证石膏的完全溶解;之后经过硼特效树脂(Amberlite IRA 743)完成硼富集及阴阳离子混合树脂(Ion ExchangeⅡ和Dowex50W×8)对硼的纯化;最终通过He改进的正热电离质谱法测定硼同位素。测得试剂石膏中的硼含量为(3.501±0.128)μg/g(n=12,RSD=3.6%),平均加标回收率为100.5%;同时加标试剂石膏的δ~(11)B值为17.98‰±0.21‰(n=3,RSD=1.2%),说明整个流程的重复性良好,可以满足(硬)石膏中硼含量及其硼同位素组成的准确测定。     

阳离子树脂交换分离-电感耦合等离子体质谱(ICP-MS)法测定地质石膏样品中硼

硼石膏近些年在水泥、沥青混合材料等领域应用广泛,其主要成分为CaSO4·2H2O和B2O3以及其他杂质,因此准确、快速测定石膏样品中的硼元素对石膏的应用、资源综合利用等方面具有重要意义。而国家标准GB/T 5484-2012《石膏分析方法》中并没有硼元素的化学分析方法,且相关文献报道也很少。目前测定硼元素主要采用电感耦合等离子体质谱法（ICP-MS）,样品前处理多采用酸溶法,而碱熔法应用不多,主要原因是碱熔后溶液中产生大量盐分影响等离子体焰的稳定性,而732型阳离子交换树脂能吸附大量的钠离子,同时吸附了钙、镍、铁及稀土等阳离子,减少盐分干扰。基于此原理,本文采用氢氧化钠碱熔-732型阳离子交换树脂交换分离,在线加入铑内标的方式,建立了ICP-MS法测定石膏中硼的方法,同时由于石膏国家标准物质不包含硼元素的含量,采用高纯硫酸钙分别与岩石标准物质、水系沉积物国家标准物质和土壤国家标准物质混合配置成人工标准物质,并讨论了熔矿体系、阳离子加入量与吸附时间、清洗液、同位素的选择等实验条件。本方法的检出限为0.76μg/g,精密度（RSD,n=7）为0.9%~1.7%,相对误差为1.56%~3.96%,加标回收率在97.5%~102%,该方法快速、准确,记忆效应小,适合石膏中硼元素的测定。     

AG50W-x8树脂分离去除钡的多原子离子对电感耦合等离子体质谱法测定稀土元素的质谱干扰

采用AG50W－x8阳离子交换树脂,以HNO3作为梯度淋洗剂,可有效地分离Ba和稀土元素,实验表明：以2mol/L HNO3淋洗时,99．5％的Ba被分离去除;以5mol/L HNO3淋洗时,稀土的回收率在96－110％之间。标准参考物质的分析结果显示测定值与标准值十分接近,表明AG50W－x8阳离子交换树脂分离可有效地去除Ba元素的多原子离子（BaO^ ,BaOH^ )对ICP－MS法测定稀土元素测定的质谱干扰,该方法准确,可靠。同时,为准确测定Eu提供了一条新的途径。     

柱撑杂多阴离子粘土的合成及表征

采用水热合成及离子交换法将Keggin结构三铁九钨镓酸盐杂多阴离子GaW9Fe3（H2O）3嵌入Zn2Al型阴离子粘土层间，得到了新型层柱状微孔材料Zn2Al－GaW9Fe3．用元素分析、XRD、IR、XPS等手段对产物的组成和结构进行了表征．结果表明，杂多阴离子嵌入Zn2Al型阴离子粘土层间，使柱撑杂多阴离子粘土具有1．0nm的通道高度．     

阴离子交换树脂分离富集/电感耦合等离子体质谱测定珊瑚中铅的同位素组成

在自制微型离子交换柱的基础上,建立了阴离子交换树脂AG1-X8分离富集珊瑚中痕量元素Pb的前处理方法,并使用高分辨电感耦合等离子体质谱(HR-ICP-MS)测定了海南橙黄滨珊瑚(porites lutea)样品中的Pb同位素比值。从全程空白值、洗脱曲线、回收率和基体分离情况等方面考察了不同洗脱剂的洗脱效果,结果表明,采用0.50 mol/L HNO3时的洗脱效果最好,方法的全程空白值为18 pg,Pb的回收率为99.6%,在洗脱过程中无拖尾现象,且能与Ca、Sr、Mg、Fe、Mn、Zn、Ba和U等珊瑚中的基体元素成功分离,对上述基体元素的去除率均能达到99.8%以上。使用该方法测得海南珊瑚样品中的207Pb/206Pb、208Pb/206Pb比值分别为0.850 5、2.087 0,相对标准偏差(RSDs,n=21)分别为0.12%和0.11%。该法质量控制良好,表明建立的AG1-X8阴离子交换树脂分离富集/HR-ICP-MS测定珊瑚中Pb的同位素组成的方法可靠,可推广应用于其它复杂样品中铅同位素组成的测定。     

多接收等离子质谱高精度测定现代人齿中Mg同位素

Mg是构成牙齿重要组分,其含量和同位素组成可记录居民生活地域、饮食习惯以及口腔健康信息等重要信息.本研究建立了高精度多接收等离子质谱(MC-ICP-MS)测定牙齿中Mg同位素方法.牙齿样品经微波消解仪消解,后采用AG50W-X8阳离子树脂分离溶液中的Mg元素,以1 mol/L HNO3为介质上柱,40 mL1 mol/L HNO3洗脱Na+等杂质离子,再以30 mL 1 mol/L HNO3收集Mg元素,60 mL 1 mol/L HNO3洗去其它杂质,蒸干Mg收集液.MC-ICP-MS进行Mg同位素组成测定.MC-ICP-MS仪器自身的质量分馏利用“样品-标准”交叉技术(“Sample-standard”bracketing technique)解决.实验结果表明,利用AG50W-X8阳离子树脂,可在保证Mg回收率的情况下,将牙齿样品中的Mg和其它基质元素彻底分离,且不造成同位素分馏.采用此方法对现代人离体牙牙釉质中Mg同位素进行分离测定,牙齿的δ25Mg在较大的范围变化(-1.38‰ ～4.59‰).本方法为利用人牙齿中Mg同位素研究Mg的暴露水平、环境污染等信息提供重要的实验和理论依据.     

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.