气相色谱-质谱联用分析兰州市大气颗粒物中的有机成分

采用大气颗粒物采样仪分别对兰州市2008年夏季、秋季和冬季和2009年春季大气中的PM2.5颗粒物样品进行采集,使用超声提取,气相色谱-质谱仪对样品中的有机成分进行了分离和定性分析.兰州市大气中共测得32种有机物,以烷烃、烯烃为主,并同时包括酯类、酮类和醇类物质.夏、秋两季的大气有机物种类变化不大,但是在冬季有机物种类变化较大.     

葛酒中葛根素及其挥发性成分分析

HPL C法定量测定了葛酒中葛根素的含量 ,葛酒中含有一定量的异黄酮类化合物葛根素 ,相同品牌不同生产批号葛酒中的葛根素含量相对稳定 ,可作为葛酒质量控制的分析方法。对葛酒中挥发性成分采用气相色谱 -质谱 (GC- MS)联机进行定性分析 ,鉴定出 10个组分。与白酒中挥发性成分比较 ,葛酒中除了含有己酸乙酯等白酒中具有的相同成分之外 ,还含有酸、酮等化合物 ,与传统的白酒工艺相比 ,葛酒的酿造过程具有一定特色。     

加速溶剂萃取-气相色谱-质谱法测定烟叶挥发性成分

用色谱指纹图谱信息量作为指标,采用均匀设计法考察了萃取时间、萃取温度和泵入萃取池溶剂量占池体积百分数三个条件对加速溶剂萃取法快速提取烟叶挥发性成分的影响,得到最优提取条件,即萃取时间为20min、萃取温度为170℃、溶剂占萃取池体积百分比为100%,由此提出了一快速测定烟叶挥发性成分的方法。所得萃取液用GC-MS检测后,采用NIST107质谱数据库检索进行定性分析,并用相对含量表示其定量结果,共鉴定出50种化学组分,占挥发油总量的87.42%,所得结果能为进一步研究烟叶化学成分提供有利的科学依据。     

金银忍冬果实中挥发性成分的GC-MS分析

研究宁夏生长的金银忍冬果实中挥发性物质的化学成分.用乙醚作溶剂,采用索氏提取法从宁夏生长的金银忍冬果实中提取挥发性物质,并通过GC-MS联用技术对挥发性成分进行了分析鉴定,用色谱峰面积归一化法计算了各成分的相对含量.从宁夏生长的金银忍冬果实中提取的挥发性物质中鉴定了32种化合物,其中含量最大的是甲基己基过氧化氢(1.3...     

气相色谱-质谱联用分析比较浙江海风藤茎及叶挥发油成分

分析比较了浙江海风藤茎及叶两个部位挥发油的化学成分.采用水蒸气蒸馏法提取,运用气相色谱-质谱联用法结合计算机检索对其化学成分进行分析和鉴定,用气相色谱面积归一法测定各组分的相对百分含量.从浙江海风藤茎及叶挥发油中分别鉴定出了30和37种化合物,其中有20种是它们共同的成分,含量最高的是喇叭茶萜醇(茎含39.62%,叶含36.80%).已鉴定挥发油成分占总挥发油含量分别为92.18%及93.15%.     

斑头雁脂肪酸的气相色谱-质谱分析

采用冷冻干燥和改进的Bligh-Dyer方法提取脂肪酸,用GC-MS测定了斑头雁腿肌、胸肌组织和卵的脂肪酸组成情况,含有脂肪酸27种,均为长链脂肪酸(C14.0以上).其中饱和脂肪酸19种,占总含量的80.577％-87.701 ％;不饱和脂肪酸8种,占脂肪酸总含量的12.298％-19.423％.在斑头雁的腿肌、胸肌和卵组织中,脂肪酸组成差异不大(P＜0.05).肌肉中含有的脂肪酸种类要多于卵组织中含有的脂肪酸种类.在斑头雁组织含有10种带有甲氧基的脂肪酸,分别占腿肌脂肪酸总量的36.175％,胸肌脂肪酸的10.401％,卵脂肪酸的45.339％.     

膜进样/飞行时间质谱实时分析水源水中挥发性有机污染物

为建立饮用水源地污染事故监控预警系统,采用膜进样/飞行时间质谱技术,对苯系物、取代苯、卤代烷等典型挥发性有机物模拟事故状况下的污染水体进行了在线监测.研究结果表明,该技术对目标有机污染物的响应时间短,对苯系物为30～70 s、对卤代烷为30 s,线性检测范围达到3～4个数量级,苯系物和氯苯的检测限小于10 μg·L-1...     

顶空固相微萃取-气相色谱-质谱法分析扶芳藤叶挥发性成分

采用顶空固相微萃取-气相色谱-质谱法分析了扶芳藤叶挥发性成分,鉴定了90种化合物,主要挥发成分及其含量为:萜类(25种,45.82%)、酯类(20种,18.26%)、脂肪烃(20种,15.06%)、芳烃化合物(3种,7.31%)、酸酐(1种,4.91%)、酮类(4种,4.2%)、卤代烃类(7种,1.52%),为进一步开发和利用扶芳藤提供基础数据。     

普洱茶挥发性成分的GC-MS分析

采用同时蒸馏萃取法(SDE)提取普洱茶的挥发性成分,经气质联用分析鉴定,应用色谱峰面积归一化测定各成分的相对含量。经过对该茶样的分析,共鉴定出44种挥发性成分,占挥发性成分总量的92.46%,其中含量较高的化合物有醇类、酯类、酸类和苯衍生物,它们分别占总量的15.47%、12.43%、8.74%、32.36%。     

GC-MS测定西瓜皮中的挥发性成分

西瓜经水蒸汽蒸馏，乙醚萃取挥发性成分，通过气相色谱－质谱联用（ＧＣ－ＭＳ）测定，发现西瓜皮中含有４２个组分，确定了其中１９个组分的结构。     

Evolved Gas Analysis by Mass Spectrometry

Abstract

The analytical applications of the evolved gas analyses (EGAs) performed by mass spectrometry for the period extending from 2005 to 2010 are collected in this review. By EGA, the nature of volatile products released by a substance subjected to a controlled temperature program are determined on-line, with the possibility to prove a supposed reaction either under isothermal or under heating conditions.     

Evolved Gas Analysis by Mass Spectrometry

Abstract: Periodic publications have been published that address advances in evolved gas analysis techniques, because the correct interpretation for the mechanism of a thermally induced reaction, involving the formation of gaseous species, is strongly dependent on the characterization of the evolved products.

When the nature of volatile products released by a substance subjected to a controlled-temperature program are online determined, the results allow one to prove a supposed reaction, either under isothermal or under heating conditions.

Very recent analytical applications of evolved gas analysis performed by mass spectrometry, selected among those published in 2012 and 2013, are collected in this review.     

The Combination of Gas Chromatography With Mass Spectrometry

Abstract

The coupling of the techniques of gas chromatography and mass spectrometry has provided the chemist with one of his most powerful analytical methods. The analysis of such diverse substances as fuels, air pollutants, food flavors, smokes, protein hydrolyzates, pesticides, lipid extracts, etc. may all require the separation and identification of the components of extremely complex mixtures.     

米兰花化学成分的GC-MS分析

采用超声波提取米兰花.然后对其化学成分进行GC-MS分析.从米兰花中分离确定了27种主要成分,其中萜类物质含量相对较高.     

A New Concept for Time-of-Flight Mass Spectrometry with Slowed-down Short-Lived Isotopes

A new concept for direct mass measurements of short-lived nuclei with an electrostatic time-of-flight mass spectrometer is described. The spectrometer can be coupled to an in-flight separator such as SHIP or FRS via a gas stopping cell and a gas-filled linear Paul trap. The time required for mass measurement is of the order of a few milliseconds allowing one to investigate nuclei with these short half-lives. A mass-resolving-power m/Δm _FWHM=50 000 has been reached. First results of the range-focusing technique are presented, which is under development for the efficient stopping and extraction of relativistic exotic nuclei. This revised version was published online in July 2006 with corrections to the Cover Date.     

1，3-二甲基尿嘧啶二聚体的飞行时间质谱裂解规律研究

采用不同进样方式、不同电子轰击能量和不同反应气压力测定了1,3 二甲基尿嘧啶二聚体(DMUD) 的4个立体异构体A、B、C、D的化学电离(CI)和电子轰击电离(EI)飞行时间质谱.不同方式所测得的CI谱结 果一致,4个异构体出现了强度不同的准分子离子峰(m/z=281),由此推断它们结构之间的相对稳定性次序为: B(trans syn)>D(cis syn)>A(trans anti)>C(cis anti).这一结论被低能量(25eV)电子轰击的EI谱所证实, 并且与合成产物的比例相吻合.EI谱用任何方式测谱均不出现分子离子峰(m/z=280),而出现其单体离子(m/z =140)且为基峰。给出了DMUD的飞行时间质谱裂解途径,同时对CI谱的裂解碎片进行了细致的讨论.     

南鹤虱挥发油化学成分的分析

采用水蒸气蒸馏法从南鹤虱中提取挥发油。试用不同类型的毛细管柱在优化条件下进行分析，共分离出33个峰，用归一化法测定其相对百分含量，并用气相色谱一质谱法对化学成分进行鉴定，共鉴定出26个成分，占挥发油总成分的78％以上．     

Use of Soft Plasma Ionization Source at Evacuated Air Atmospheres in Time-of-Flight Mass Spectrometry to Suppress Fragmentation of Volatile Organic Compounds

This study describes a measuring system for mass spectrometry, consisting of a glow discharge ionization source for soft plasma ionization and a time-of-flight mass spectrometer, to detect toxic volatile organic compounds rapidly and easily. It is the most important to determine how the complicated fragmentation of such compounds can be suppressed to occur so as to recognize the mass spectra of the volatile organic compounds as their fingerprints. The novelty of this work is that the optimal discharge condition for the soft plasma ionization–time-of-flight mass spectrometer system could be selected, so that the parent mass peak of analyte molecules could be observed both with high sensitivity and with little or no fragmentation of them. Use of air gas at a pressure of 1000 Pa provided the most favorable result for these criteria, whereas, in a previous report, the soft plasma ionization source operating with argon at a pressure of 346 Pa had yielded additional mass peaks of the fragmented species. The reason for this would be explained by the fact that energetic electrons in the plasma, which principally cause the fragmentation of the volatile organic compounds, have lower number density at higher gas pressures, through de-accelerated collisions with the plasma gas.     

吹扫捕集与气相色谱-质谱联用测定水体中的芳烃化合物

利用吹扫捕集-气相色谱-质谱联用技术,对化工厂附近有可能受污染的地表水进行了定性和定量分析。同时对吹扫捕集的试验条件进行了优化,得到了满意的结果。