Development of a novel in vivo lung perfusion(IVLP)procedure allows localized delivery of high-dose doxorubicin(DOX)for targeting residual micrometastatic disease in the lungs.However,DOX delivery via IVLP requires ca...Development of a novel in vivo lung perfusion(IVLP)procedure allows localized delivery of high-dose doxorubicin(DOX)for targeting residual micrometastatic disease in the lungs.However,DOX delivery via IVLP requires careful monitoring of drug level to ensure tissue concentrations of this agent remain in the therapeutic window.A small dimension nitinol wire coated with a sorbent of biocompatible morphology(Bio-SPME)has been clinically evaluated for in vivo lung tissue extraction and determination of DOX and its key metabolites.The in vivo Bio-SPME-IVLP experiments were performed on pig model over various(150 and 225 mg/m^(2))drug doses,and during human clinical trial.Two patients with metastatic osteosarcoma were treated with a single 5 and 7 μg/mL(respectively)dose of DOX during a 3-h IVLP.In both pig and human cases,DOX tissue levels presented similar trends during IVLP.Human lung tissue concentrations of drug ranged between 15 and 293 μg/g over the course of the IVLP procedure.In addition to DOX levels,Bio-SPME followed by liquid chromatography-mass spectrometry analysis generated 64 metabolic features during endogenous metabolite screening,providing information about lung status during drug administration.Real-time monitoring of DOX levels in the lungs can be performed effectively throughout the IVLP procedure by in vivo Bio-SPME chemical biopsy approach.Bio-SPME also extracted various endogenous molecules,thus providing a real-time snapshot of the physiology of the cells,which might assist in the tailoring of personalized treatment strategy.展开更多
Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been sy...Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...展开更多
A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorp...A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.展开更多
Solid phase microextraction (SPME) is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling...Solid phase microextraction (SPME) is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph (GC) for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 ~m PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride (SF6) and perfluoromethylcyclohexane (PMCH) with adequate sensitivity.展开更多
Base on the previous work in laboratory, a novel polyaniline doped with polydimethylsiloxane coating was developed on a stainless steel wire for solid phase microextraction(SPME) by electroplating method. This elect...Base on the previous work in laboratory, a novel polyaniline doped with polydimethylsiloxane coating was developed on a stainless steel wire for solid phase microextraction(SPME) by electroplating method. This electroplating method not only has advantages of ease preparation and simple equipments required, but also increases the lifetime of the SPME fiber. The composite fiber(polyaniline/ polydimethylsiloxane(PANI/PDMS)) was evaluated by analyzing n-tridecane, n-tetradecane and n-pentadecane in aqueous sample. The new fiber coating showed comprehensive abilities to extract alkanes compounds. The relative standard deviations were found to be 6.8%-10.33%.展开更多
To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collec...To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collected using head-space solid phase microextraction (HS-SPME), and were analyzed using a gas chromatograph-mass spectrophotometer (GC- MS). A total of 37 compounds were identified from the sample extracts. Aldehydes, alcohols, and esters were the major constituents. The aroma components behaved differently during the fruit developmental period. C6 aldehydes and aromatic aldehydes were the main aldehydes in the sweet cherry fruit. The contents of C6 aldehydes increased quickly to 84.16% in the color stage, then decreased as ripening proceeded, and then, the contents decreased to 59.20 and 55.58% at the commercial stage and the ripe stage, respectively. The aromatic aldehydes (benzaldehyde) increased as ripening proceeded, and the maximum was found at the ripe stage. Alcohols of sweet cherry fruit included C6 alcohols and aromatic alcohols. The content of (E)-2-hexen-l-ol increased as ripening proceeded. The maximum was found at the commercial stage; alcohol was only found at the ripe stage. Ester components included ethyl acetate, butanoic acid ethyl ester, hexanoic acid ethyl ester, which increased as the fruit ripened. Hexanal, (E)-2-hexenal, benzaldehyde, (E)-2-hexen-l-ol, ethyl acetate, and hexanoic acid ethyl ester were the characteristic aroma components of sweet cherry fruit. These aroma components started to form drastically at the color stage, and the main aroma was formed at the commercial stage, which then turned bad at the ripe stage because of the presence of alcohol. So the optimal harvest time of sweet cherry was at the commercial stage.展开更多
The determination of emitted Biogenic Volatile Compounds (BioVOCs) profile via Field Air Analysis (FAA) - Solid Phase Micro Extraction (75μm Carboxen/PDMS portable field sampler) was performed using GC-MS. The ...The determination of emitted Biogenic Volatile Compounds (BioVOCs) profile via Field Air Analysis (FAA) - Solid Phase Micro Extraction (75μm Carboxen/PDMS portable field sampler) was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO's World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, 13-pinene, 6-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the'national road a higher amount of benzene derivatives (ben- zene, toluene, o-xylene, p-xylene and ethylbenzene) were observed. In the site relatively close to the road a marked decrease of benzene deriva- tives was observed. In the sites close to conifers (i.e. Fir, Pine and Larch) the terpenic content observed was higher than in the site close to the mixed forest (mainly large-leaf and some conifers). Some terpenes were observed also in the high-quote meadow site, although of lower abun- dance than in the other sites. The highest abundance of terpenes was ob- served in the Pinus cerebra (Swiss Pine) site.展开更多
Owing to frequent environmental monitoring of tetrabromobisphenol-A(TBBPA)analogs and their potential ecotoxicological effects on organisms,analysis of trace levels of TBBPA analogs with more non-polar and less water-...Owing to frequent environmental monitoring of tetrabromobisphenol-A(TBBPA)analogs and their potential ecotoxicological effects on organisms,analysis of trace levels of TBBPA analogs with more non-polar and less water-soluble characteristics is of great significance for studying their environmental behaviors and toxic effects.Herein,a fast and sensitive technique is developed for directly detecting aqueous TBBPA analogs,including TBBPA mono(allyl ether)(TBBPA-MAE),TBBPA mono(2,3-dibromopropyl ether)(TBBPAMDBPE),TBBPA mono(2-hydroxyethyl ether)(TBBPA-MHEE)and TBBPA mono(glycidyl ether)(TBBPAMGE),by combining solid phase microextraction(SPME)based on porous covalent organic frameworks(Porous-COFs)with constant flow desorption ionization-mass spectrometry(CFDI-MS).As chromatographic separation is replaced by constant flow desorption,each sample can be analyzed within 7 min.The hierarchical porous structures(microporous,mesoporous and macroporous)of COFs lead to the enhanced mass transfer and the easier accessibility of active sites to TBBPA analogs,so that the extraction efficiency is 2.3-3.6 times higher than pure microporous COFs,and far superior to commercial coatings.The detection limit and quantification limit of this method are 0.1-1 and 0.4-3.2 ng/L,respectively.Ultratrace levels of TBBPA analogs from 5.0 ng/L to 66 ng/L have been successfully detected in river and sea water samples,showing great potential for subsequent studies of their environmental behaviors and toxicological effects.展开更多
Normothermic ex vivo lung perfusion(NEVLP)has emerged as a modernized organ preservation technique that allows for detailed assessment of donor lung function prior to transplantation.The main goal of this study was to...Normothermic ex vivo lung perfusion(NEVLP)has emerged as a modernized organ preservation technique that allows for detailed assessment of donor lung function prior to transplantation.The main goal of this study was to identify potential biomarkers of lung function and/or injury during a prolonged(19 h)NEVLP procedure using in vivo solid-phase microextraction(SPME)technology followed by liquid chromatography-high resolution mass spectrometry(LC-HRMS).The use of minimally invasive in vivo SPME fibers for repeated sampling of biological tissue permits the monitoring and evaluation of biochemical changes and alterations in the metabolomic profile of the lung.These in vivo SPME fibers were directly introduced into the lung and were also used to extract metabolites(on-site SPME)from fresh perfusate samples collected alongside lung samplings.A subsequent goal of the study was to assess the feasibility of SPME as an in vivo method in metabolomics studies,in comparison to the traditional inlab metabolomics workflow.Several upregulated biochemical pathways involved in pro-and antiinflammatory responses,as well as lipid metabolism,were observed during extended lung perfusion,especially between the 11th and 12th hours of the procedure,in both lung and perfusate samples.However,several unstable and/or short-lived metabolites,such as neuroprostanes,have been extracted from lung tissue in vivo using SPME fibers.On-site monitoring of the metabolomic profiles of both lung tissues through in vivo SPME and perfusate samples on site throughout the prolonged NEVLP procedure can be effectively performed using in vivo SPME technology.展开更多
[ Objective] This study aimed to investigate the ehangos of aroma components in mango fruit at different post-harvest stages. [ Method] The aroma com- ponents in ' Keitt' mango fruit at 3,6, 9 and 13 d postharvest w...[ Objective] This study aimed to investigate the ehangos of aroma components in mango fruit at different post-harvest stages. [ Method] The aroma com- ponents in ' Keitt' mango fruit at 3,6, 9 and 13 d postharvest were extracted using heM-space solid phase mieroextraction (HS-SPME) and analyzed by gas chre- matograph-rnass speetrephotometer (GC-MS). [ Result] The results showed that a total of 42 aroma compounds were identified from the mango samples at four sta- ges. To be specific, monoterpene and sesquiterpene were the major components; at 3, 6, 9 and 13 d postharvest, the relative contents of terpene were 94.24%, 98.91%, 55.32% and 95.97%, respectively. [ Conclusion] IS-( + )-3-earene is the characteristic aroma component in ripe fruit of ' Keitt' mango. The aroma of mango fruit is also affected by ester, alcohol and aldehyde compounds.展开更多
The present study was carried out to determine the essential oil composition of aerial parts of two endemic umbelliferae herbs (Malabaila lasiocarpa Boiss. and Stenotaenia macrocarpa Freyn & Sint. ex Freyn) collect...The present study was carried out to determine the essential oil composition of aerial parts of two endemic umbelliferae herbs (Malabaila lasiocarpa Boiss. and Stenotaenia macrocarpa Freyn & Sint. ex Freyn) collected from Bingol (Turkey), using headspace solid-phase microextraction method and gas chromatography (GC) interfaced with mass spectrometer analysis. Forty six and 43 compounds were identified for M. lasiocarpa and S. macrocarpa, respectively, representing 91.40% and 90.86% of their respective essential oils. Germacrene D (20.71%),β-elemene (12.40%), spathulenol (11.60%) and β-selinene (9.67%) were identified as the major compound of M. lasiocarpa. β-sesquiphellandrene (19.68%), hexyl isobutyrate (12.65%) and octanal (9.53%) were found to be the major compounds ofS. macrocarpa. Essential oil composition ofM. lasiocarpa has been determined for the first time and the results have been discussed in view of chemotaxonomy, natural products and potential usefulness of these plants.展开更多
Headspace solid phase microextraction chromatography (HS-SPME/GC) was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary ma...Headspace solid phase microextraction chromatography (HS-SPME/GC) was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity (R = 0.999) was found, and the repeatability (n = 1 l) was 6.31%. The results indicated that hexanal is linearly related to peroxide value (PV) only intermediate PV ranges (10-18 meq/kg). The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.展开更多
Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparallele...Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparalleled selectivity.Herein,through a laser microfabrication method in situ,the free-standing,super hydrophilic and vacancy-rich TiO_(2-x)/Ti is successfully synthesized.Using blue TiO_(x)/Ti(B-TiO_(x)/Ti)as preconcentrated substrate,a nanomolar-level limit of detection of 12 nmol/L at 1385 cm–1,is confirmed using crystal violet(CV)bacteriostat as a model under 532 nm excitation.Furthermore,the results demonstrate that the SERS enhancement mechanism is via the moderate adulteration of oxygen vacancy,which leads to a narrow value of band gap and increases the ICTP of substrate to molecules.Using a hand-held extractor assembled with B-TiO_(x)/Ti microfiber,the operando analysis of mixtures distributed information excited in different parts of Asian carp is facilely achieved.This work guides the controlled synthesis of vacancy-rich TiO_(2-x)/Ti nanostructure and its application in ultrasensitive extraction-SERS detection.It also provides the direction for the rapid and operando transmission of biological information with temporal and spatial concentration distribution in human tissues by highly sensitized materials.展开更多
This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyze...This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS).Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compound scould be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized,representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (-0.785), and β-ionone (-0.763). On the basis of these 10 compounds, a model (correlation coefficient of89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjingtea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MStechnique.展开更多
Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle s...Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.展开更多
The volatile organic compounds(VOCs) are emitted by a wide array of products, which include a variety of chemicals, some of them may have short- and long-term adverse health effects. Several analytical instrument incl...The volatile organic compounds(VOCs) are emitted by a wide array of products, which include a variety of chemicals, some of them may have short- and long-term adverse health effects. Several analytical instrument including gas chromatograph, high preferment liquid chromatograph, mass spectrometry and solid phase microextraction (SPME) technique were used in this study. The results showed the aldehyde and ketone components of Chinese fir wood were little composed of formaldehyde, syn- acetaldehyde, anti-acetadehyde and acrolein, VOCs obtained by Tenax GR absorber consisted of the major component cedrene (42.92%) and another 28 components, and the major components of the VOCs from the sample by using solid phase microextraction (SPME) technique were cedrene and cedrol.展开更多
文摘Development of a novel in vivo lung perfusion(IVLP)procedure allows localized delivery of high-dose doxorubicin(DOX)for targeting residual micrometastatic disease in the lungs.However,DOX delivery via IVLP requires careful monitoring of drug level to ensure tissue concentrations of this agent remain in the therapeutic window.A small dimension nitinol wire coated with a sorbent of biocompatible morphology(Bio-SPME)has been clinically evaluated for in vivo lung tissue extraction and determination of DOX and its key metabolites.The in vivo Bio-SPME-IVLP experiments were performed on pig model over various(150 and 225 mg/m^(2))drug doses,and during human clinical trial.Two patients with metastatic osteosarcoma were treated with a single 5 and 7 μg/mL(respectively)dose of DOX during a 3-h IVLP.In both pig and human cases,DOX tissue levels presented similar trends during IVLP.Human lung tissue concentrations of drug ranged between 15 and 293 μg/g over the course of the IVLP procedure.In addition to DOX levels,Bio-SPME followed by liquid chromatography-mass spectrometry analysis generated 64 metabolic features during endogenous metabolite screening,providing information about lung status during drug administration.Real-time monitoring of DOX levels in the lungs can be performed effectively throughout the IVLP procedure by in vivo Bio-SPME chemical biopsy approach.Bio-SPME also extracted various endogenous molecules,thus providing a real-time snapshot of the physiology of the cells,which might assist in the tailoring of personalized treatment strategy.
基金the support of the National Natural Science Foundation of China(No.20575051).
文摘Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...
文摘A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.
基金Contract No.200-2009-31933,awarded by the National Institute for Occupational Safety and Health(NIOSH)
文摘Solid phase microextraction (SPME) is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph (GC) for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 ~m PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride (SF6) and perfluoromethylcyclohexane (PMCH) with adequate sensitivity.
文摘Base on the previous work in laboratory, a novel polyaniline doped with polydimethylsiloxane coating was developed on a stainless steel wire for solid phase microextraction(SPME) by electroplating method. This electroplating method not only has advantages of ease preparation and simple equipments required, but also increases the lifetime of the SPME fiber. The composite fiber(polyaniline/ polydimethylsiloxane(PANI/PDMS)) was evaluated by analyzing n-tridecane, n-tetradecane and n-pentadecane in aqueous sample. The new fiber coating showed comprehensive abilities to extract alkanes compounds. The relative standard deviations were found to be 6.8%-10.33%.
文摘To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collected using head-space solid phase microextraction (HS-SPME), and were analyzed using a gas chromatograph-mass spectrophotometer (GC- MS). A total of 37 compounds were identified from the sample extracts. Aldehydes, alcohols, and esters were the major constituents. The aroma components behaved differently during the fruit developmental period. C6 aldehydes and aromatic aldehydes were the main aldehydes in the sweet cherry fruit. The contents of C6 aldehydes increased quickly to 84.16% in the color stage, then decreased as ripening proceeded, and then, the contents decreased to 59.20 and 55.58% at the commercial stage and the ripe stage, respectively. The aromatic aldehydes (benzaldehyde) increased as ripening proceeded, and the maximum was found at the ripe stage. Alcohols of sweet cherry fruit included C6 alcohols and aromatic alcohols. The content of (E)-2-hexen-l-ol increased as ripening proceeded. The maximum was found at the commercial stage; alcohol was only found at the ripe stage. Ester components included ethyl acetate, butanoic acid ethyl ester, hexanoic acid ethyl ester, which increased as the fruit ripened. Hexanal, (E)-2-hexenal, benzaldehyde, (E)-2-hexen-l-ol, ethyl acetate, and hexanoic acid ethyl ester were the characteristic aroma components of sweet cherry fruit. These aroma components started to form drastically at the color stage, and the main aroma was formed at the commercial stage, which then turned bad at the ripe stage because of the presence of alcohol. So the optimal harvest time of sweet cherry was at the commercial stage.
文摘The determination of emitted Biogenic Volatile Compounds (BioVOCs) profile via Field Air Analysis (FAA) - Solid Phase Micro Extraction (75μm Carboxen/PDMS portable field sampler) was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO's World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, 13-pinene, 6-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the'national road a higher amount of benzene derivatives (ben- zene, toluene, o-xylene, p-xylene and ethylbenzene) were observed. In the site relatively close to the road a marked decrease of benzene deriva- tives was observed. In the sites close to conifers (i.e. Fir, Pine and Larch) the terpenic content observed was higher than in the site close to the mixed forest (mainly large-leaf and some conifers). Some terpenes were observed also in the high-quote meadow site, although of lower abun- dance than in the other sites. The highest abundance of terpenes was ob- served in the Pinus cerebra (Swiss Pine) site.
基金financially supported by the National Natural Science Foundation of China(Nos.21922402,21976185)the Innovation Academy for Green Manufacture,Chinese Academy of Sciences(No.IAGM2020C20)。
文摘Owing to frequent environmental monitoring of tetrabromobisphenol-A(TBBPA)analogs and their potential ecotoxicological effects on organisms,analysis of trace levels of TBBPA analogs with more non-polar and less water-soluble characteristics is of great significance for studying their environmental behaviors and toxic effects.Herein,a fast and sensitive technique is developed for directly detecting aqueous TBBPA analogs,including TBBPA mono(allyl ether)(TBBPA-MAE),TBBPA mono(2,3-dibromopropyl ether)(TBBPAMDBPE),TBBPA mono(2-hydroxyethyl ether)(TBBPA-MHEE)and TBBPA mono(glycidyl ether)(TBBPAMGE),by combining solid phase microextraction(SPME)based on porous covalent organic frameworks(Porous-COFs)with constant flow desorption ionization-mass spectrometry(CFDI-MS).As chromatographic separation is replaced by constant flow desorption,each sample can be analyzed within 7 min.The hierarchical porous structures(microporous,mesoporous and macroporous)of COFs lead to the enhanced mass transfer and the easier accessibility of active sites to TBBPA analogs,so that the extraction efficiency is 2.3-3.6 times higher than pure microporous COFs,and far superior to commercial coatings.The detection limit and quantification limit of this method are 0.1-1 and 0.4-3.2 ng/L,respectively.Ultratrace levels of TBBPA analogs from 5.0 ng/L to 66 ng/L have been successfully detected in river and sea water samples,showing great potential for subsequent studies of their environmental behaviors and toxicological effects.
基金the Canadian Institute of Health Research(CIHR)-Natural Sciences and Engineering Research Council(NSERC)of the Canada Collaborative Health Research Projects program for their financial support(Grant No.:355935)the Natural Sciences and Engineering Research Council of Canada Industrial Research Chair(IRC)program.
文摘Normothermic ex vivo lung perfusion(NEVLP)has emerged as a modernized organ preservation technique that allows for detailed assessment of donor lung function prior to transplantation.The main goal of this study was to identify potential biomarkers of lung function and/or injury during a prolonged(19 h)NEVLP procedure using in vivo solid-phase microextraction(SPME)technology followed by liquid chromatography-high resolution mass spectrometry(LC-HRMS).The use of minimally invasive in vivo SPME fibers for repeated sampling of biological tissue permits the monitoring and evaluation of biochemical changes and alterations in the metabolomic profile of the lung.These in vivo SPME fibers were directly introduced into the lung and were also used to extract metabolites(on-site SPME)from fresh perfusate samples collected alongside lung samplings.A subsequent goal of the study was to assess the feasibility of SPME as an in vivo method in metabolomics studies,in comparison to the traditional inlab metabolomics workflow.Several upregulated biochemical pathways involved in pro-and antiinflammatory responses,as well as lipid metabolism,were observed during extended lung perfusion,especially between the 11th and 12th hours of the procedure,in both lung and perfusate samples.However,several unstable and/or short-lived metabolites,such as neuroprostanes,have been extracted from lung tissue in vivo using SPME fibers.On-site monitoring of the metabolomic profiles of both lung tissues through in vivo SPME and perfusate samples on site throughout the prolonged NEVLP procedure can be effectively performed using in vivo SPME technology.
基金Supported by Central Nonprofit Basic Scientific Research Project for the Scientific Research Institutes of China(No.1630062012003)
文摘[ Objective] This study aimed to investigate the ehangos of aroma components in mango fruit at different post-harvest stages. [ Method] The aroma com- ponents in ' Keitt' mango fruit at 3,6, 9 and 13 d postharvest were extracted using heM-space solid phase mieroextraction (HS-SPME) and analyzed by gas chre- matograph-rnass speetrephotometer (GC-MS). [ Result] The results showed that a total of 42 aroma compounds were identified from the mango samples at four sta- ges. To be specific, monoterpene and sesquiterpene were the major components; at 3, 6, 9 and 13 d postharvest, the relative contents of terpene were 94.24%, 98.91%, 55.32% and 95.97%, respectively. [ Conclusion] IS-( + )-3-earene is the characteristic aroma component in ripe fruit of ' Keitt' mango. The aroma of mango fruit is also affected by ester, alcohol and aldehyde compounds.
文摘The present study was carried out to determine the essential oil composition of aerial parts of two endemic umbelliferae herbs (Malabaila lasiocarpa Boiss. and Stenotaenia macrocarpa Freyn & Sint. ex Freyn) collected from Bingol (Turkey), using headspace solid-phase microextraction method and gas chromatography (GC) interfaced with mass spectrometer analysis. Forty six and 43 compounds were identified for M. lasiocarpa and S. macrocarpa, respectively, representing 91.40% and 90.86% of their respective essential oils. Germacrene D (20.71%),β-elemene (12.40%), spathulenol (11.60%) and β-selinene (9.67%) were identified as the major compound of M. lasiocarpa. β-sesquiphellandrene (19.68%), hexyl isobutyrate (12.65%) and octanal (9.53%) were found to be the major compounds ofS. macrocarpa. Essential oil composition ofM. lasiocarpa has been determined for the first time and the results have been discussed in view of chemotaxonomy, natural products and potential usefulness of these plants.
文摘Headspace solid phase microextraction chromatography (HS-SPME/GC) was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity (R = 0.999) was found, and the repeatability (n = 1 l) was 6.31%. The results indicated that hexanal is linearly related to peroxide value (PV) only intermediate PV ranges (10-18 meq/kg). The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.
基金supported by National Key Research and Development Program of China(No.2023YFB3210400)Major Scientific and Technological Innovation Project of Shandong Province(No.2021CXGC010603)+1 种基金Natural Science Foundation of Shandong Province(Nos.ZR2020QE057,ZR2020QE071,ZR2020LLZ006)Innovative Team Project of Jinan(No.2021GXRC019)。
文摘Semiconductor-molecule surface-enhanced Raman scattering(SERS),especially the stronger interfacial charge transfer process(ICTP),represents a frontier in the field of SERS with spectral reproducibility and unparalleled selectivity.Herein,through a laser microfabrication method in situ,the free-standing,super hydrophilic and vacancy-rich TiO_(2-x)/Ti is successfully synthesized.Using blue TiO_(x)/Ti(B-TiO_(x)/Ti)as preconcentrated substrate,a nanomolar-level limit of detection of 12 nmol/L at 1385 cm–1,is confirmed using crystal violet(CV)bacteriostat as a model under 532 nm excitation.Furthermore,the results demonstrate that the SERS enhancement mechanism is via the moderate adulteration of oxygen vacancy,which leads to a narrow value of band gap and increases the ICTP of substrate to molecules.Using a hand-held extractor assembled with B-TiO_(x)/Ti microfiber,the operando analysis of mixtures distributed information excited in different parts of Asian carp is facilely achieved.This work guides the controlled synthesis of vacancy-rich TiO_(2-x)/Ti nanostructure and its application in ultrasensitive extraction-SERS detection.It also provides the direction for the rapid and operando transmission of biological information with temporal and spatial concentration distribution in human tissues by highly sensitized materials.
文摘This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS).Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compound scould be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized,representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (-0.785), and β-ionone (-0.763). On the basis of these 10 compounds, a model (correlation coefficient of89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjingtea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MStechnique.
基金This research was partially supported by China Scholarship Council(CSC 201707070113).
文摘Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.
基金Supported by key foundation research project (G1999016001) of China and Japan International Cooperation Agency.
文摘The volatile organic compounds(VOCs) are emitted by a wide array of products, which include a variety of chemicals, some of them may have short- and long-term adverse health effects. Several analytical instrument including gas chromatograph, high preferment liquid chromatograph, mass spectrometry and solid phase microextraction (SPME) technique were used in this study. The results showed the aldehyde and ketone components of Chinese fir wood were little composed of formaldehyde, syn- acetaldehyde, anti-acetadehyde and acrolein, VOCs obtained by Tenax GR absorber consisted of the major component cedrene (42.92%) and another 28 components, and the major components of the VOCs from the sample by using solid phase microextraction (SPME) technique were cedrene and cedrol.