An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector...An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector (FID). As a sample diluent in a headspace sampling, dimethylformamide (DMF) was selected owing to its high capacity for dissolving both bixin-based and norbixin-based annatto extracts. The quantification of residual solvents was performed using the external standard method. The linearity of the calibration curves was assured with relative coefficients (R2) that were greater than 0.999. The recoveries of all standard solvents spiked in the annatto extracts were in the range from 95.1% to 107.1% to verify the accuracy and the relative standard deviation (RSD%) values (n = 3) were in the range from 0.57% to 3.31%. The quantification limits (QL) were sufficiently lower than the limits specified by Joint FAO/WHO Expert Committee on Food Additives (JECFA). With the established HSGC method, six residual solvents (methanol, ethanol, 2-propanol, acetone, ethyl acetate, and hexane) in 23 commercial annatto-extract products that consist of seven bixin-based and 16 norbixin-based products were quantified. The levels of residual ethyl acetate and hexane in all products were lower than the specified limits of JECFA. However, three samples of bixin-based products showed higher levels of residual 2-propanol (approximately 313.9 - 427.7 ppm) than the specified limit. Other bixin products also showed higher concentrations of residual methanol (approximately 166.6 - 394.7 ppm) and residual acetone (approximately 75.2 - 179.8 ppm) than the limits of JECFA. In the case of norbixin-based products, nine samples showed higher levels of residual acetone (approximately 42.6 - 139.5 ppm) than the limits of JECFA. This is the first survey of residual solvents in annatto extracts using the validated HSGC method.展开更多
Quality control of ginseng currently is mainly based on ginsenoside analysis,but rarely focuses on the volatile organic components.In the current work,an untargeted metabolomics approach,by headspace solid-phase micro...Quality control of ginseng currently is mainly based on ginsenoside analysis,but rarely focuses on the volatile organic components.In the current work,an untargeted metabolomics approach,by headspace solid-phase micro-extraction gas chromatography/mass spectrometry(HS-SPME-GC/MS),was elaborated and further employed to holistically compare the compositional difference of the volatile components simultaneously from 12 Panax herbal medicines,which included P.ginseng(PG),P.quinquefolius(PQ),P.notoginseng(PN),red ginseng(PGR),P.ginseng leaf(PGL),P.quinquefolius leaf(PQL),P.notoginseng leaf(PNL),P.ginseng flower(PGF),P.quinquefolius flower(PQF),P.notoginseng flower(PNF),P.japonicus(PJ),and P.japonicus var.major(PJvm).Chromatographic separation was performed on an HP-5MS elastic quartz capillary column using helium as the carrier gas,enabling good resolution within 1 h.We were able to characterize totally 259 volatile compounds,including 82 terpenes(T),46 alcohols(Alc),29 ketones(K),25 aldehydes(Ald),21 esters(E),and the others.By analyzing 90 batches of ginseng samples based on the untargeted metabolomics workflows,236 differential ions were unveiled,and accordingly 36 differential volatile components were discovered.It is the first report that simultaneously compares the compositional difference of volatile components among 12 Panax herbal medicines,and useful information is provided for the quality control of ginseng aside from the well-known ginsenosides.展开更多
This paper briefly expounds the basic principle and classification of headspace gas chromatography,summarizes its application in food analysis,environmental analysis and medical analysis,and forecasts the application ...This paper briefly expounds the basic principle and classification of headspace gas chromatography,summarizes its application in food analysis,environmental analysis and medical analysis,and forecasts the application prospect of headspace gas chromatography in analytical chemistry in the future.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
The vapor–liquid equilibrium(VLE)data of a-pinene+camphene+[abietic acid+palustric acid+neoabietic acid]and a-pinene+longifolene+[abietic acid+palustric acid+neoabietic acid]systems at 313.15 K,333.15 K and 358.15 K ...The vapor–liquid equilibrium(VLE)data of a-pinene+camphene+[abietic acid+palustric acid+neoabietic acid]and a-pinene+longifolene+[abietic acid+palustric acid+neoabietic acid]systems at 313.15 K,333.15 K and 358.15 K were measured by headspace gas chromatography(HSGC).These data was compared with the predictions value by conductor-like screening model for realistic solvation(COSMO-RS).Moreover,the calculated data of COSMO-RS and Non-Random Two-Liquids(NRTL)models showed good agreement with the experimental data.It was found that the three resin acids inhibited the volatility of a-pinene,camphene and longifolene and resulted in the decrease of total pressure.Moreover,HE(HB)contributes the most to the excess enthalpy and the hydrogen bonding interaction is the dominant intermolecular force of a-pinene,camphene and longifolene with the three resin acids.In addition,the geometric structures optimization and binding energy were obtained by the DFT to further illustrate the hydrogen bonding interaction and the effects of the addition of the three resin acids on the isothermal VLE.展开更多
[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds i...[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control.展开更多
文摘An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector (FID). As a sample diluent in a headspace sampling, dimethylformamide (DMF) was selected owing to its high capacity for dissolving both bixin-based and norbixin-based annatto extracts. The quantification of residual solvents was performed using the external standard method. The linearity of the calibration curves was assured with relative coefficients (R2) that were greater than 0.999. The recoveries of all standard solvents spiked in the annatto extracts were in the range from 95.1% to 107.1% to verify the accuracy and the relative standard deviation (RSD%) values (n = 3) were in the range from 0.57% to 3.31%. The quantification limits (QL) were sufficiently lower than the limits specified by Joint FAO/WHO Expert Committee on Food Additives (JECFA). With the established HSGC method, six residual solvents (methanol, ethanol, 2-propanol, acetone, ethyl acetate, and hexane) in 23 commercial annatto-extract products that consist of seven bixin-based and 16 norbixin-based products were quantified. The levels of residual ethyl acetate and hexane in all products were lower than the specified limits of JECFA. However, three samples of bixin-based products showed higher levels of residual 2-propanol (approximately 313.9 - 427.7 ppm) than the specified limit. Other bixin products also showed higher concentrations of residual methanol (approximately 166.6 - 394.7 ppm) and residual acetone (approximately 75.2 - 179.8 ppm) than the limits of JECFA. In the case of norbixin-based products, nine samples showed higher levels of residual acetone (approximately 42.6 - 139.5 ppm) than the limits of JECFA. This is the first survey of residual solvents in annatto extracts using the validated HSGC method.
基金National Natural Science Foundation of China(Grant No.81872996)Natural Science Foundation of Tianjin of China(Grant No.20JCYBJC00060).
文摘Quality control of ginseng currently is mainly based on ginsenoside analysis,but rarely focuses on the volatile organic components.In the current work,an untargeted metabolomics approach,by headspace solid-phase micro-extraction gas chromatography/mass spectrometry(HS-SPME-GC/MS),was elaborated and further employed to holistically compare the compositional difference of the volatile components simultaneously from 12 Panax herbal medicines,which included P.ginseng(PG),P.quinquefolius(PQ),P.notoginseng(PN),red ginseng(PGR),P.ginseng leaf(PGL),P.quinquefolius leaf(PQL),P.notoginseng leaf(PNL),P.ginseng flower(PGF),P.quinquefolius flower(PQF),P.notoginseng flower(PNF),P.japonicus(PJ),and P.japonicus var.major(PJvm).Chromatographic separation was performed on an HP-5MS elastic quartz capillary column using helium as the carrier gas,enabling good resolution within 1 h.We were able to characterize totally 259 volatile compounds,including 82 terpenes(T),46 alcohols(Alc),29 ketones(K),25 aldehydes(Ald),21 esters(E),and the others.By analyzing 90 batches of ginseng samples based on the untargeted metabolomics workflows,236 differential ions were unveiled,and accordingly 36 differential volatile components were discovered.It is the first report that simultaneously compares the compositional difference of volatile components among 12 Panax herbal medicines,and useful information is provided for the quality control of ginseng aside from the well-known ginsenosides.
基金Supported by Special Fund for Scientific Research Project from the Education Department of Shaanxi Province(16JK1275)National Science and Technology Innovation Support Fund Project for College Students(16XK046)
文摘This paper briefly expounds the basic principle and classification of headspace gas chromatography,summarizes its application in food analysis,environmental analysis and medical analysis,and forecasts the application prospect of headspace gas chromatography in analytical chemistry in the future.
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.
基金support for this work from the National Natural Science Foundation of China(31960294,32160349)Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2017Z005,2020Z005)+1 种基金the Project for Cultivating New Century Academic and Technology Leaders of Nanning City(2020010)the High-Performance Computing Platform of Guangxi University.
文摘The vapor–liquid equilibrium(VLE)data of a-pinene+camphene+[abietic acid+palustric acid+neoabietic acid]and a-pinene+longifolene+[abietic acid+palustric acid+neoabietic acid]systems at 313.15 K,333.15 K and 358.15 K were measured by headspace gas chromatography(HSGC).These data was compared with the predictions value by conductor-like screening model for realistic solvation(COSMO-RS).Moreover,the calculated data of COSMO-RS and Non-Random Two-Liquids(NRTL)models showed good agreement with the experimental data.It was found that the three resin acids inhibited the volatility of a-pinene,camphene and longifolene and resulted in the decrease of total pressure.Moreover,HE(HB)contributes the most to the excess enthalpy and the hydrogen bonding interaction is the dominant intermolecular force of a-pinene,camphene and longifolene with the three resin acids.In addition,the geometric structures optimization and binding energy were obtained by the DFT to further illustrate the hydrogen bonding interaction and the effects of the addition of the three resin acids on the isothermal VLE.
文摘[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control.
