We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituen...We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.展开更多
[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) com...[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.展开更多
In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile com...In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.展开更多
采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(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 spectrometr...采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(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)技术解析了天龙泉米香型白酒挥发性组分特征。采用该技术并结合多种检索比对方式在天龙泉米香型白酒中鉴定出挥发性化合物505种,其中339种为天龙泉米香型白酒的潜在香气活性组分,包括86种酯类、50种芳香族、42种醇类、40种醛类、32种含氧杂环化合物、30种酮类、25种萜烯类、19种有机酸类、11种含硫化合物和4种含氮杂环化合物,表明了米香型白酒中香气成分的多样性和复杂性。在挥发性香气化合物含量角度上,不同贮存期的米香型白酒样品呈现明显差异,在时间维度上具有一定规律。其中,变化较大的化合物是醇类化合物、酯类化合物和醛类化合物,可能是受到了企业生产工艺的调整和陈化过程中发生的化学反应共同影响。该研究更深入地认识了米香型白酒的挥发性风味物质,丰富了米香型白酒风味化学的研究体系。展开更多
为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(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...为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(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-TOF-MS)对汽蒸前后六堡茶进行分析。结果表明,汽蒸能够有效提升六堡茶品质,汤色由橙色、较亮转变为橙红明亮,滋味方面酸味、涩味以及醇厚感得到有效改善,香气方面汽蒸后堆味、豆豉味等不利于六堡茶品质的气味得到有效去除,发酵气也得到减弱;分别从汽蒸前后六堡茶中检测出189种和188种挥发性化合物,碳氢类化合物最多,其次为醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、含氮类、内酯类和酚类化合物。T检验分析表明,汽蒸前后六堡茶中碳氢类、醛类、呋喃类和酚类化合物总含量无显著差异(p>0.05);内酯类和含氮类化合物的总含量显著降低(p<0.05);醇类、酮类、酯类和甲氧基苯类的总含量极显著降低(p<0.01),其中碳氢类、醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、酚类、内酯类和含氮类化合物中差异显著(p<0.05)的化合物分别有10、3、3、5、2、1、2、0、2种和1种;差异极显著(p<0.01)的化合物分别有32、24、11、4、14、6、6、1、2种和4种。展开更多
文摘We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.
基金Supported by Key Science and Technology Project of Gansu Province(1302NKDA028)Science and Technology Planning Project of Lanzhou(2010-1-239+2 种基金 2016-3-4)Talent Project of Lanzhou Science and Technology Bureau(2015-RC-87)Project of Science and Technology Cooperation between Gansu Academy of Agricultural Sciences and Local Areas(2017GAAS63)
文摘[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.
文摘In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.
文摘采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(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)技术解析了天龙泉米香型白酒挥发性组分特征。采用该技术并结合多种检索比对方式在天龙泉米香型白酒中鉴定出挥发性化合物505种,其中339种为天龙泉米香型白酒的潜在香气活性组分,包括86种酯类、50种芳香族、42种醇类、40种醛类、32种含氧杂环化合物、30种酮类、25种萜烯类、19种有机酸类、11种含硫化合物和4种含氮杂环化合物,表明了米香型白酒中香气成分的多样性和复杂性。在挥发性香气化合物含量角度上,不同贮存期的米香型白酒样品呈现明显差异,在时间维度上具有一定规律。其中,变化较大的化合物是醇类化合物、酯类化合物和醛类化合物,可能是受到了企业生产工艺的调整和陈化过程中发生的化学反应共同影响。该研究更深入地认识了米香型白酒的挥发性风味物质,丰富了米香型白酒风味化学的研究体系。
文摘为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(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-TOF-MS)对汽蒸前后六堡茶进行分析。结果表明,汽蒸能够有效提升六堡茶品质,汤色由橙色、较亮转变为橙红明亮,滋味方面酸味、涩味以及醇厚感得到有效改善,香气方面汽蒸后堆味、豆豉味等不利于六堡茶品质的气味得到有效去除,发酵气也得到减弱;分别从汽蒸前后六堡茶中检测出189种和188种挥发性化合物,碳氢类化合物最多,其次为醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、含氮类、内酯类和酚类化合物。T检验分析表明,汽蒸前后六堡茶中碳氢类、醛类、呋喃类和酚类化合物总含量无显著差异(p>0.05);内酯类和含氮类化合物的总含量显著降低(p<0.05);醇类、酮类、酯类和甲氧基苯类的总含量极显著降低(p<0.01),其中碳氢类、醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、酚类、内酯类和含氮类化合物中差异显著(p<0.05)的化合物分别有10、3、3、5、2、1、2、0、2种和1种;差异极显著(p<0.01)的化合物分别有32、24、11、4、14、6、6、1、2种和4种。
