应用固态热调制技术的全二维气相色谱-质谱联用法对工业废水中有机污染物的检测

采用新型固态热调制技术的全二维气相色谱-质谱联用法对某工业废水进行分析,定性检出162种主要的有机污染物。结果表明,有机污染物主要由苯系物和萘系物组成;同类化合物在全二维气相色谱谱图上呈规律性排布,可以方便地对性质相近的化合物进行归类分析;全二维气相色谱-质谱法具有更大的峰容量、更高的分辨率和灵敏度,是复杂样品的准确可靠的分析方法。     

全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)用于烟叶中挥发、半挥发性碱性化合物的组成研究

建立了烟叶中挥发性、半挥发性碱性化合物组成研究的全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)分析方法, 并用所建立的方法对香料烟中碱性化合物进行了表征. 对比了一维气相色谱和全二维色谱方法用于烟叶碱性组分组成分析的效果. 一维色谱质谱方法共鉴定出45种碱性化合物. 用所建立的全二维气相色谱方法, 采用TOFMS谱图库检索结合全二维特有的包含结构信息的二维谱图, 通过族分离和结构谱图鉴定, 鉴定出了香料烟中挥发性、半挥发性碱性组分共92种. 包括吡咯类化合物6种, 吡啶类化合物39种, 吡嗪类化合物10种, 苯胺类化合物11种, 喹啉类化合物11种, 吲哚类4种和其他类化合物11种. 同时对不同类别的化合物在二维气相色谱上的分布模式进行了研究. 研究结果表明, 全二维色谱飞行时间质谱的高分辨率和特有的定性手段适合于烟叶这类复杂植物体系的化学组成研究.     

全二维气相色谱/飞行时间质谱用于烟叶中酸性成分的分离与分析

建立了烟叶中酸性化合物(挥发性、 半挥发性羧酸类和酚类)组成研究的全二维气相色谱/飞行时间质谱(GC×GC-TOFMS)分析方法, 并用此方法对香料烟中的酸性化合物进行了表征. 用同时蒸馏萃取样品的前处理方法, 采用TOFMS谱图库检索结合全二维特有的包含结构信息的二维谱图, 通过族分离和结构谱图, 鉴定出了香料烟中143种挥发性及半挥发性酸性组分, 包括10种酸酐和呋喃二酮, 43种有机酸和90种酚类化合物. 同时对不同类别的化合物在二维气相色谱上的分布模式进行了研究. 结果表明, 全二维气相色谱飞行时间质谱的高分辨率非常适合于烟叶这类复杂体系的分离分析.     

全二维气相色谱分析持久性有机污染物的应用进展

持久性有机污染物（POPs）组分复杂,在自然界中超痕量存在,其分离分析十分困难。全二维气相色谱（GC×GC）作为一种新型色谱技术,与传统的一维气相色谱相比,具有峰容量大、分辨率和灵敏度高等优势,越来越广泛地应用于环境有机污染物的分析。该文综述了近十年来全二维气相色谱在持久性有机污染物分析中的应用进展,主要包括全二维气相色谱在解决一些复杂POPs定性定量分析难题方面的应用,如二恶英、毒杀芬和短链氯化石蜡等;概述了全二维气相色谱对多种POPs同时定性定量分析的应用进展;讨论了全二维气相色谱在非目标有机污染物筛查分析中的应用,并对发展趋势及相关应用前景进行了总结展望。     

全二维气相色谱/飞行时间质谱用于卷烟主流烟气中酚类化合物的表征

建立了卷烟主流烟气粒相物中酚类化合物组成研究的全二维气相色谱／飞行时间质谱方法，并用所建立的方法对一种市售混合型卷烟主流烟气粒相物中的酚类馏分组成进行了表征．采用TOFMS谱图库检索辅以二维“结构谱图”的定性手段，初步鉴定出了其中250个酚类化合物．这些酚类化合物包括66个烷基苯酚、47个烯基苯酚、57个萘酚、17个苯基苯酚、32个甲氧基苯酚、9个酚酮和15个酚醛化合物．同时对不同类型的酚类化合物在二维气相色谱上的分布模式进行了讨论．     

离线全二维逆流色谱-液相色谱分离莪术油成分

中药挥发油成分复杂,一维色谱分离由于有限的峰容量难以完全分离中药挥发油成分,全二维气相色谱为分离挥发油成分提供了有力的方法,然而气相色谱一般无法用于天然活性成分的筛选。为建立挥发油成分全二维色谱分析新方法,研究建立以液相色谱为基础的全二维色谱分离分析方法。本文主要研究全二维逆流色谱-液相色谱分离莪术油成分的方法,并探讨两种色谱技术之间的正交性,为活性成分筛选提供新的技术支持。通过优化离线全二维逆流色谱-液相色谱分离方法,对全二维色谱峰容量、正交性和空间覆盖率进行度量。优化液相色谱分析条件并筛选逆流色谱分离两相溶剂体系,通过比色法筛选了逆流色谱两相溶剂体系并采用下相为流动相进行梯度洗脱。在290～375 min采用推挤洗脱,莪术油在第一维逆流色谱分离中达到了良好的分离。第二维反相高效液相色谱的流动相组成为乙腈(A)和水(B)。梯度洗脱程序为0～10 min, 50%A～65%A; 10～14 min, 65%A; 14～21 min, 65%A～85%A; 21～25 min, 85%A～95%A; 25～30 min, 95%A～55%A; 30～40 min, 55%A。在上述条件下...     

生物制药研究中的多维色谱

对全二维气相色谱(GC×GC)、全二维液相色谱(HPLC×HPLC)、多维毛细管电泳等多维分离技术在生物制药研究中的应用进行了综述,其中对作者所在研究组在全二维气相色谱应用于中药及固相萃取-液相色谱联用分析系统等方面的工作做了重点介绍。由所综述的生物制药研究得出结论：多维分离方法以其高分辨、快速、自动化等特点已经在生物制药领域显示出它的巨大优势,并将发挥更大的作用。     

稠油中饱和烃复杂混合物成分解析及其意义

利用两根极性不同的毛细柱,在全二维气相色谱上分析辽河油田遭受严重生物降解形成的稠油饱和烃组分,可以将传统色谱分析时形成的“基线鼓包”即不可分辨的复杂混合物（Unresolved Complex Mixtures）分开．根据饱和烃全二维气相色谱谱图的族分离特点和瓦片效应,结合飞行时间质谱提供的质谱信息初步解析不可分辨的复杂混合物主要成分．发现常规色谱分析时形成的所谓“基线鼓包”是由成千上万、含量相对较低的不同取代基的环状化合物组成,这些化合物在一维色谱上以分子量递增的顺序排列,在二维色谱上以极性的差异或者环的多少排列．C24之前的第一组不可分辨的复杂混合物主要由环己烷为基本单元的单环、双环和三环烷烃类化合物组成,信噪比在100以上的化合物数量约为饱和烃总数量的75％,质量分数是饱和烃总量的80％以上,是饱和烃的主要组成部分．C24之后出现的第二组不可分辨的复杂混合物主要由四个环或者五个环为基本单元的化合物组成,信噪比在100以上的化合物数量约为饱和烃总数量的17％,质量分数是饱和烃总量的0．5％．对稠油中这些不可分辨的复杂混合物的解析有助于对其成因机理的认识和高效开采方案的制定．     

气相色谱-质谱联用仪常见故障的排除

介绍气相色谱-质谱联用仪的常见故障：与质谱仪调谐相关的故障、与校准和灵敏度相关的故障及与色谱图和质谱图相关的故障，给出了产生故障的可能原因，提出了故障排除的方法。     

全二维气相色谱在食品风味化学成分分析中的应用

食品风味是评价食品品质特征的重要指标。食品风味物质分析通常采用一维气相色谱或气相色谱-质谱联用法,但由于某些食品风味成分组成和基质复杂,无法用一维气相色谱将其完全分离。全二维气相色谱将分离机理不同而又相互独立的两根色谱柱以正交方式组合,显著提升了色谱分离能力和分析速度,可满足食品中风味化学成分的二次分离。该文综述了全二维气相色谱技术在未经二次加工的食用农产品(如水果、蔬菜和肉类)和经过二次加工的食品(如乳制品、饮品和调味品)中风味化学成分分析中的应用,展现了全二维气相色谱技术的特点,并为食品风味的解析提供参考。     

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.