As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a ca...As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.展开更多
Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） ...Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.展开更多
采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOFMS)和定量描述分析法(quan...采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOFMS)和定量描述分析法(quantitative descriptive analysis,QDA),从物质和感官2个角度表征了不同等级汾酒的香气特征。不同等级汾酒中共检测出400种挥发性化合物,高等级汾酒中酯类物质种类较多。通过香气数据库筛选具有香气特征的组分进行半定量分析,发现不同等级汾酒中香气化合物的相对含量具有显著差异。QDA结果显示,汾00和汾10主要表现为糟香、酸香、粮香和曲香等香气特征,而高等级的汾20和汾30则主要呈现出花香、果香、甜香、青草香和陈香等香气特征。通过多元统计分析将物质与感官相关联,筛选了与不同等级汾酒特定感官特征相关的潜在化合物。该研究不仅可以丰富清香型白酒风味化学的理论体系,同时也为生产上质量调控及工艺改进提供了数据支撑。展开更多
研究以黄鹤楼大清香和汾酒为主要研究对象,采用全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOF MS)技术对六种南北派大清香白酒的挥发性成分进行分析...研究以黄鹤楼大清香和汾酒为主要研究对象,采用全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOF MS)技术对六种南北派大清香白酒的挥发性成分进行分析,在6种样品中共筛选出302种香气贡献度较高的挥发性化合物,其中种类最多的是酯类化合物,共检测到88种,其次是醇类化合物检测到52种,机酸类化合物18种,醛酮类化合物47种,烃类化合物32种,呋喃类化合物8种,萜烯类化合物9种,芳香族化合物40种,吡嗪类化合物3种,其他类化合物5种。由于呋喃类和萜烯类化合物通常具有特殊的香气,对清香型白酒的香气产生重要影响,因而,本文在鉴定出的挥发性香气组分中着重对比分析了呋喃类和萜烯类。通过GC×GC-TOFMS技术在六种清香型白酒中确定出40种主要区分南北派大清香白酒香气的差异性挥发物质,其中酯类化合物4种,醇类化合物14种,醛酮类化合物15种,芳香族化合物4种,稀萜类化合物1种,其他类化合物2种。该研究为清香型白酒的挥发性香气组分分析与感官特征评价提供依据。展开更多
基金funded by the Major State Basic Research Development Program of China(973 project,Grant No.2012CB214803)National Science and Technology Major Project of China(Grant No. 2016ZX05003-005)National Natural Science Foundation of China(Grant Nos.41322017 and 41472100)
文摘As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.
基金funded by the National Natural Science Foundation of China(Grant No.41172126)the State Key Laboratory of Petroleum Resources and Prospecting(PRP/indep-2-1402)
文摘Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.
文摘研究以黄鹤楼大清香和汾酒为主要研究对象,采用全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOF MS)技术对六种南北派大清香白酒的挥发性成分进行分析,在6种样品中共筛选出302种香气贡献度较高的挥发性化合物,其中种类最多的是酯类化合物,共检测到88种,其次是醇类化合物检测到52种,机酸类化合物18种,醛酮类化合物47种,烃类化合物32种,呋喃类化合物8种,萜烯类化合物9种,芳香族化合物40种,吡嗪类化合物3种,其他类化合物5种。由于呋喃类和萜烯类化合物通常具有特殊的香气,对清香型白酒的香气产生重要影响,因而,本文在鉴定出的挥发性香气组分中着重对比分析了呋喃类和萜烯类。通过GC×GC-TOFMS技术在六种清香型白酒中确定出40种主要区分南北派大清香白酒香气的差异性挥发物质,其中酯类化合物4种,醇类化合物14种,醛酮类化合物15种,芳香族化合物4种,稀萜类化合物1种,其他类化合物2种。该研究为清香型白酒的挥发性香气组分分析与感官特征评价提供依据。
