在线质谱仪在车内VOCs现场快速监测中的应用

挥发性有机物(VOCs)影响车内空气质量和驾乘者的身心健康。自主研发的在线挥发性有机物质谱仪(SPI-MS 2000),实现了有机物分子的单光子电离,产生无碎片的分子离子,可实现秒级响应,仪器的质量分辨率优于800 FWHM,质量精度优于0.02 amu,对甲苯的测定限优于3μg/m^3,且在3~8000μg/m^3范围内有良好的线性关系。将该仪器应用于某客车车内空气的在线检测:在5 s内检测到20多种微克~毫克每立方米量级的有机物。该仪器在车内VOCs现场快速监测方面有广泛的应用前景。     

人体呼出挥发性有机物的口罩微萃取气相色谱-质谱分析

人体呼气中含有大量与人类行为和健康状况有关的挥发性有机物(VOCs).本研究采用口罩微萃取方法富集人体呼出VOCs,并联用3种气相色谱-质谱仪(GC-MS)对呼出VOCs进行分析鉴定与比对.优化了固相微萃取探针及富集采样时间;通过对比正常生理呼出VOCs和口罩的背景信号,探索了人体经过不同的食物摄入和口腔护理对呼出VO...     

吹扫捕集-气相色谱-质谱法测定生活用水及塑料水管中20种挥发性有机物的含量北大核心CSCD

近年来,随着工业污染的加重,挥发性有机物(VOCs)已成为水体常见污染物之一[1]。VOCs具有迁移性、持久性和毒性[2],若长期饮用含VOCs的水将严重损害人体健康,会对人体免疫系统、中枢神经系统和一些内脏器官等产生毒害作用,因此其被列为优先控制污染物[3-5]。     

顶空固相微萃取-气相色谱-质谱法同时测定饮用水源水中24种VOCs

建立了同时测定饮用水源水中24种挥发性有机物(VOCs)的顶空固相微萃取-气相色谱-质谱法.用75 μm CarboxenTM-Polydimethylsiloxane(CAR-PDMS)固相微萃取柱顶空萃取水样中的VOCs,VOCs用气相色谱-质谱联用仪检测,采用内标法定量.对萃取柱涂层、样品盐度、萃取温度和萃取时间等样品前处理条件进行了优化,VOCs的检出限在0.03～0.31 μg/L之间,线性相关系数r＞0.996(二氯甲烷和三氯甲烷除外).对饮用水源水实际水样0.50μg/L和1.00 μg/L两个加标浓度水平的回收率进行了测定,三氯甲烷回收率均值分别为104％和142％,其余VOCs回收率分别为90.0％～120％和88.0％～110％,除二氯甲烷和三氯甲烷外,其余VOCs测定结果的相对标准偏差均小于15.0％(n=6).该方法适用于饮用水源水中挥发性有机物的监测分析.     

气质联用法测定饮用水中29种挥发性有机物

挥发性有机物(VOCs)具有高挥发性、类脂物可溶性、易被皮肤、粘膜吸收等特点,对环境和人体有较大的影响和危害.新<生活饮用水卫生标准>(GB/T 5749-2006)[1]中VOCs的检测项目从原来的2项增加到25项.顶空气相色谱是过去测定水中VOCs的常用方法,但该法灵敏度较低,不适于数十种挥发性有机物同时检测[2].新技术吹扫捕集-气质联用法(P&T-GC-MS)能同时分析测定多种物质,前处理方式也较简便,因此成为测定水中VOCs的推荐方法[3-6].     

便携式GC-MS在挥发性有机物应急监测中的应用

建立了便携式GC-MS测定空气中37种挥发性有机物(VOCs)的方法,采用便携式GC-MS配置的手持探头采集大气样品,然后用便携式GC-MS进行检测.该方法能快速、有效地对空气中的37种挥发性有机物进行定性和定量,具有相关性好(r>0.995)、检出限低(0.070×10-9 ～0.94×10-9 (体积分数))、精密度好(RSD小于7.7%)、准确度高(回收率为92% ～114%)的特点,适用于大气中挥发性有机污染物的应急监测.     

水体中挥发性有机污染物的应急监测

建立了以吹扫捕集-气相色谱-质谱法为主的挥发性有机物(VOCs)应急监测方法。采用内标法对环境水体中的VOCs含量进行检测,54种VOCs的回收率为93.7%~136%,相对标准偏差为2.67%~14.2%,检出限为0.07~1.87μg/L。同时应用相对响应因子(RRF)快速定量数据库对水样中VOCs的含量进行估算,通过与内标法测量值比对,验证了数据库用于水体污染事故中VOCs应急监测的可行性。     

国内首创的SPIMS-1000在线挥发性有机物质谱仪

概述了国内首款具有完全自主知识产权的商品化在线挥发性有机物质谱仪(SPIMS-1000)。SPIMS-1000融合了膜富集、紫外光单光子软电离(SPI)和反射式飞行时间质谱等多种技术,实现了对挥发性有机物(VOCs)及半挥发性有机物(SVOCs)的在线定性定量分析。对其基本原理、仪器设计、分析参数及应用进行了介绍。     

GC-MS法测定水源水中的半挥发性有机物

我国于2002年6月1日实施了地表水环境质量标准(GB3838-2002),其中集中式生活饮用水地表水源地特定项目中规定了68种有机污染物的监测,包括挥发性有机物(VOCs)和半挥发性有机物(SVOCs),其中半挥发性有机物的类别较多,有硝基苯、氯苯、苯胺、苯酚、有机氯农药、有机磷农药、多环芳烃和多氯联苯等有机污染物,分析方法以气相色谱为主。     

便携式气相色谱-质谱仪测定空气中挥发性有机污染物的准确性

便携式气相色谱-质谱仪(便携式GC-MS)能同时对多组分复杂有机物进行定性定量分析,在环境监测尤其是事故现场应急监测中发挥越来越重要的作用。本文比较了便携式GC-MS与EPATO-14A方法分析测定环境空气中低浓度挥发性有机物(VOCs)的性能,并探讨了利用定量环(loop环)模式测定高浓度VOCs的准确度。结果表明,采用内标标准曲线定量,HAPSITE便携式GC-MS测定空气中VOCs的检出限与EPATO-14A方法相当,准确度和精密度略低,但均符合环境监测分析的要求。利用loop环可对大部分10-6级的高浓度VOCs样品进行较为准确的测定,在突发性环境污染事故中可以得到基本准确的结果。     

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.