Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation ...Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation and direct steam distillation method. Among their composition, the main components are terpene compounds, which account for 93.926% (mass fraction, the same below) and 85.843% of essential oils extracted from Shatian shaddock peel and Sweet shaddock peel, respectively. Although nootkatone is the major contributor of shaddock characteristic scent, and its contents are 1.069% and 1.749% of essential oils from Sweet shaddock peel and Shatian shaddock peel, respectively. The results show that squeeze-steam distillation gives higher yield and good quality of essential oil and the compositions of essential oils from two kinds of shaddock peels are different, but the main contributors of the shaddock scent are the same.展开更多
Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively...Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively inert, causing no irritation and allergies. Poly(ethylene oxide)(PEO) hydrogels were prepared using pentaerythritol tetra-acrylate(PETRA) as UV crosslinking agent. A simple, accurate, and robust quantitation method was developed based on gas chromatographic techniques(GC), which is suitable for routine analysis of residual PETRA monomers in these hydrogels. Unreacted PETRA was initially identified using gas chromatography–mass spectrometry(GC–MS). The quantitation of analyte was performed and validated using gas chromatography equipped with a flame ionization detector(GC–FID). A linear relationship was obtained over the range of 0.0002%–0.0450%(m/m) with a correlation coefficient(r2)greater than 0.99. The recovery( 4 90%), intra-day precision(%RSD o 0.67), inter-day precision(%RSD o2.5%), and robustness(%RSD o1.62%) of the method were within the acceptable values. The limit of detection(LOD) and limit of quantitation(LOQ) were 0.0001%(m/m) and 0.0002%(m/m), respectively.This assay provides a simple and quick way of screening for residual acrylate monomer in hydrogels.展开更多
采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometr...采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)和电子鼻技术分析6种果酒中的挥发性成分,评价果酒风味轮廓特征的差异性。结果表明,GC-FID定量测定樱桃李酒,其中异戊醇、活性戊醇、β-苯乙醇含量最高,乙酸乙酯含量最低;木瓜酒中正丙醇、2,3-丁二醇、癸酸乙酯、乙酸含量最高; 3-羟基-2-丁酮含量在樱桃李酒中最高,山楂酒、甜橙酒中最少。HP-SPME-GC-MS鉴定果酒中挥发性物质94种,其中醇类23种,酯类43种,醛酮类10种,酸类8种,酚类2种,苯环类5种,烷烃类3种。山楂酒、菠萝酒、木瓜酒、甜橙酒、无花果酒和樱桃李酒中香气物质数量分别为34、44、45、45、33、47种。其中山楂酒、木瓜酒和无花果酒中未检出酚类、烷烃类物质。电子鼻对不同果酒香气的区分效果无重叠,W5S传感器区分果酒香气能力最强。比较而言,菠萝酒和樱桃李酒的口感更圆润,香气更愉悦,感官得分最高。展开更多
[Objective] This study aimed to analyze the chemical composition and yield of essential oil and n-hexane extract from moso bamboo to find active compounds with potential value. [Method] Essential oil and n-hexane extr...[Objective] This study aimed to analyze the chemical composition and yield of essential oil and n-hexane extract from moso bamboo to find active compounds with potential value. [Method] Essential oil and n-hexane extract were respectively extracted from moso bamboo of four different ages by using hydrodistillation and ultrasonic-assisted extraction with n-hexane, and analyzed with gas chromatography/mass spectrometry （GC/MS）. [Result] The results show that cedrol （46.39%） is the first principal volatile component in essential oil of the middle stem of 7-year old moso bamboo; dibutyl phthalate （59.46%） is the first principal volatile component in n-hexane extract of the middle stem of 3-year old moso bamboo; yield of n-hexane extract is higher than that of essential oil from moso bamboo. [Conclusion] Cedrol is an active compound with potential value.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
The solid-phase microextraction （SPME） combined with gas chromatography/mass spectrometry （GC/MS） was used to determine and analyze organic pollutants in coking wastewater. Based on the fact that the main compound...The solid-phase microextraction （SPME） combined with gas chromatography/mass spectrometry （GC/MS） was used to determine and analyze organic pollutants in coking wastewater. Based on the fact that the main compounds in the wastewater were organics, some key parameters of the SPME were optimized. The method has good linearity （ its correlation coefficients 〉 0.99） in the range determined,its relative standard deviations （RSD） are less than 15%, and its recovery is from 87.9% to 128.1% with the lowest quantification limit of 5 ~g/L. This method has been used to measure 15 organic pollutants in wastewater from a certain coking plant. The results show that compared with the conventional method,it can save an hour in pretreatment time. It is a fast, low-cost, accurate, simple and efficient analytical method indeed.展开更多
[Objectives] To analyze volatile components of flowers and leaves of Thymus mongolicus. [Methods]Volatile components of collected T. mongolicus flower and leaves were separated by headspace solid-phase microextraction...[Objectives] To analyze volatile components of flowers and leaves of Thymus mongolicus. [Methods]Volatile components of collected T. mongolicus flower and leaves were separated by headspace solid-phase microextraction( SPME) and identified by gas chromatography/mass spectrometry( GC/MS) and normallized by peak area. [Results] A total of 24 and 14 compounds were identified from flowers and leaves of T. mongolicus in the total ion chromatogram,accounting for 99. 573% and 97. 187% of the total peak area,respectively. Main components of flowers and leaves of T. mongolicus include phenols and terpenes,and thymol accounts for 35. 38% and 49. 13% of flowers and leaves of T. mongolicus,respectively. [Conclusions] SPME-GC/MS can be applied in analyzing volatile components of flowers and leaves of T. mongolicus,to provide basis for further development and utilization of T. mongolicus.展开更多
This paper aims at testing oxygen and benzene contents in gasoline by mid-infrared spectroscopy.The experimental results prove that infrared spectroscopy(IR)is reliable.Compared with gas chromatography(GC)technology,t...This paper aims at testing oxygen and benzene contents in gasoline by mid-infrared spectroscopy.The experimental results prove that infrared spectroscopy(IR)is reliable.Compared with gas chromatography(GC)technology,this paper draws a conclusion that IR has several advantages,including rapid analysis,excellent repeatability and low analysis cost.展开更多
The detector,as well as being an essential supporting device for the gas chromatography(GC) has also played a critical role in the development of the technique as a whole.The mass spectrometer(MS) is still the commonl...The detector,as well as being an essential supporting device for the gas chromatography(GC) has also played a critical role in the development of the technique as a whole.The mass spectrometer(MS) is still the commonly praised detector as before.In fact,the information of fragmentation patterns is seldom used in practice,and the GC-MS instrument is even more expensive.For today's analytical problems,it seems that element specific detectors can and should be used for many applications rather than GC-MS.展开更多
With the improvement of living quality, high-oleic peanuts have drawn people’s attention. Increasing oleic acid content of peanut oil should be desired for improving shelf life and potential health benefits. The fla...With the improvement of living quality, high-oleic peanuts have drawn people’s attention. Increasing oleic acid content of peanut oil should be desired for improving shelf life and potential health benefits. The flavor is among the most important quality attributes for commercial acceptance of peanuts products. The volatile components of high-oleic pea-nuts oil and normal-oleic lines were compared in this research. First, volatile components of peanut oils were analyzed and identified by solid-phase microextraction/gas chroma- tography/mass spectrometry （SPME/GC/MS）. Then principal components analysis （PCA） was used to identify principal volatile components in peanut oils of different cultivars fo卜 lowing three different processing methods, including roasting, boiling and roasting, and roasting by microwave-assisted. The results showed that there were obvious differences of the volatile components between high-oleic and normal peanut oils. Among different pro-cessing method of peanuts, there was no clear separation on volatile components observed between roasting and boiling and roasting by microwave-assisted. Moreover, the same genotype had the similar flavor characteristic. Different processing methods had no signifi-cant effect on volatile components in peanut oils.展开更多
文摘Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation and direct steam distillation method. Among their composition, the main components are terpene compounds, which account for 93.926% (mass fraction, the same below) and 85.843% of essential oils extracted from Shatian shaddock peel and Sweet shaddock peel, respectively. Although nootkatone is the major contributor of shaddock characteristic scent, and its contents are 1.069% and 1.749% of essential oils from Sweet shaddock peel and Shatian shaddock peel, respectively. The results show that squeeze-steam distillation gives higher yield and good quality of essential oil and the compositions of essential oils from two kinds of shaddock peels are different, but the main contributors of the shaddock scent are the same.
文摘Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively inert, causing no irritation and allergies. Poly(ethylene oxide)(PEO) hydrogels were prepared using pentaerythritol tetra-acrylate(PETRA) as UV crosslinking agent. A simple, accurate, and robust quantitation method was developed based on gas chromatographic techniques(GC), which is suitable for routine analysis of residual PETRA monomers in these hydrogels. Unreacted PETRA was initially identified using gas chromatography–mass spectrometry(GC–MS). The quantitation of analyte was performed and validated using gas chromatography equipped with a flame ionization detector(GC–FID). A linear relationship was obtained over the range of 0.0002%–0.0450%(m/m) with a correlation coefficient(r2)greater than 0.99. The recovery( 4 90%), intra-day precision(%RSD o 0.67), inter-day precision(%RSD o2.5%), and robustness(%RSD o1.62%) of the method were within the acceptable values. The limit of detection(LOD) and limit of quantitation(LOQ) were 0.0001%(m/m) and 0.0002%(m/m), respectively.This assay provides a simple and quick way of screening for residual acrylate monomer in hydrogels.
文摘采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)和电子鼻技术分析6种果酒中的挥发性成分,评价果酒风味轮廓特征的差异性。结果表明,GC-FID定量测定樱桃李酒,其中异戊醇、活性戊醇、β-苯乙醇含量最高,乙酸乙酯含量最低;木瓜酒中正丙醇、2,3-丁二醇、癸酸乙酯、乙酸含量最高; 3-羟基-2-丁酮含量在樱桃李酒中最高,山楂酒、甜橙酒中最少。HP-SPME-GC-MS鉴定果酒中挥发性物质94种,其中醇类23种,酯类43种,醛酮类10种,酸类8种,酚类2种,苯环类5种,烷烃类3种。山楂酒、菠萝酒、木瓜酒、甜橙酒、无花果酒和樱桃李酒中香气物质数量分别为34、44、45、45、33、47种。其中山楂酒、木瓜酒和无花果酒中未检出酚类、烷烃类物质。电子鼻对不同果酒香气的区分效果无重叠,W5S传感器区分果酒香气能力最强。比较而言,菠萝酒和樱桃李酒的口感更圆润,香气更愉悦,感官得分最高。
基金Supported by Sub-project of the "Eleventh Five-Year" National Science and Technology Support Program (2006BAD19B04)~~
文摘[Objective] This study aimed to analyze the chemical composition and yield of essential oil and n-hexane extract from moso bamboo to find active compounds with potential value. [Method] Essential oil and n-hexane extract were respectively extracted from moso bamboo of four different ages by using hydrodistillation and ultrasonic-assisted extraction with n-hexane, and analyzed with gas chromatography/mass spectrometry （GC/MS）. [Result] The results show that cedrol （46.39%） is the first principal volatile component in essential oil of the middle stem of 7-year old moso bamboo; dibutyl phthalate （59.46%） is the first principal volatile component in n-hexane extract of the middle stem of 3-year old moso bamboo; yield of n-hexane extract is higher than that of essential oil from moso bamboo. [Conclusion] Cedrol is an active compound with potential value.
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The solid-phase microextraction （SPME） combined with gas chromatography/mass spectrometry （GC/MS） was used to determine and analyze organic pollutants in coking wastewater. Based on the fact that the main compounds in the wastewater were organics, some key parameters of the SPME were optimized. The method has good linearity （ its correlation coefficients 〉 0.99） in the range determined,its relative standard deviations （RSD） are less than 15%, and its recovery is from 87.9% to 128.1% with the lowest quantification limit of 5 ~g/L. This method has been used to measure 15 organic pollutants in wastewater from a certain coking plant. The results show that compared with the conventional method,it can save an hour in pretreatment time. It is a fast, low-cost, accurate, simple and efficient analytical method indeed.
基金Supported by Natural Science Foundation Project of Inner Mongolia Autonomous Region(2015MS0324)Scientific Research Service Project of Chifeng University(KYFW-16-05)
文摘[Objectives] To analyze volatile components of flowers and leaves of Thymus mongolicus. [Methods]Volatile components of collected T. mongolicus flower and leaves were separated by headspace solid-phase microextraction( SPME) and identified by gas chromatography/mass spectrometry( GC/MS) and normallized by peak area. [Results] A total of 24 and 14 compounds were identified from flowers and leaves of T. mongolicus in the total ion chromatogram,accounting for 99. 573% and 97. 187% of the total peak area,respectively. Main components of flowers and leaves of T. mongolicus include phenols and terpenes,and thymol accounts for 35. 38% and 49. 13% of flowers and leaves of T. mongolicus,respectively. [Conclusions] SPME-GC/MS can be applied in analyzing volatile components of flowers and leaves of T. mongolicus,to provide basis for further development and utilization of T. mongolicus.
文摘This paper aims at testing oxygen and benzene contents in gasoline by mid-infrared spectroscopy.The experimental results prove that infrared spectroscopy(IR)is reliable.Compared with gas chromatography(GC)technology,this paper draws a conclusion that IR has several advantages,including rapid analysis,excellent repeatability and low analysis cost.
文摘The detector,as well as being an essential supporting device for the gas chromatography(GC) has also played a critical role in the development of the technique as a whole.The mass spectrometer(MS) is still the commonly praised detector as before.In fact,the information of fragmentation patterns is seldom used in practice,and the GC-MS instrument is even more expensive.For today's analytical problems,it seems that element specific detectors can and should be used for many applications rather than GC-MS.
文摘With the improvement of living quality, high-oleic peanuts have drawn people’s attention. Increasing oleic acid content of peanut oil should be desired for improving shelf life and potential health benefits. The flavor is among the most important quality attributes for commercial acceptance of peanuts products. The volatile components of high-oleic pea-nuts oil and normal-oleic lines were compared in this research. First, volatile components of peanut oils were analyzed and identified by solid-phase microextraction/gas chroma- tography/mass spectrometry （SPME/GC/MS）. Then principal components analysis （PCA） was used to identify principal volatile components in peanut oils of different cultivars fo卜 lowing three different processing methods, including roasting, boiling and roasting, and roasting by microwave-assisted. The results showed that there were obvious differences of the volatile components between high-oleic and normal peanut oils. Among different pro-cessing method of peanuts, there was no clear separation on volatile components observed between roasting and boiling and roasting by microwave-assisted. Moreover, the same genotype had the similar flavor characteristic. Different processing methods had no signifi-cant effect on volatile components in peanut oils.
