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The extraction of geraniol from palmarosa oil using hydrotropic solvents was investigated. Palmarosa oil possesses an appealing rose aroma and properties like anti - inflammatory, antifungal, and antioxidant due to the presence of geraniol. The extraction of geraniol from palmarosa oil by using distillation methods like steam dis tillation and fractional distillation was a laborious process. So hydrotropes were tried for extraction. The geraniol yield and purity depend on parameters like concentration of hydrotrope, solvent volume ratio, and time period. Using the Box Benkhem Desig n (BBD), the extraction process was optimized. One of the major advantages of using hydrotropic solvents is that they were classified as green solvents, and recovery of solvents is also possible. To reduce the extraction time probe sonication is carried ou t. Different hydrotropic solvents with probe sonication are done on palmarosa oil by altering various process parameters to study the separation, yield, and purity.
Se investigó la extracción de geraniol del aceite de palmarosa utilizando solventes hidrotrópicos. El aceite de palmarosa posee un atractivo aroma a rosa y propiedades antiinflamatorias, antifúngicas y antioxidantes debido a la pr esencia de geraniol. La extracción de geraniol del aceite de palmarosa mediante métodos de destilación como la destilación por vapor y la destilación fraccionada ha sido un proceso laborioso. Por lo tanto, se probaron los hidrotropos para la extracción. El rendimiento y la pureza del geraniol dependen de parámetros como la concentración del hidrotropo, la relación de volumen del solvente y el período de tiempo. Se optimizó el proceso de extracción usando el diseño Box Benkhem (BBD). Una de las principales v entajas de usar solventes hidrotrópicos es que se clasifican como solventes verdes y también es posible recuperar los solventes. Para reducir el tiempo de extracción, se lleva a cabo una sonda de ultrasonido. Se realizan diferentes solventes hidrotropos co n sonda de ultrasonido en el aceite de palmarosa alterando varios parámetros del proceso para estudiar la separación, el rendimiento y la pureza.
Тема - темы
Plant Oils/chemistry , Cymbopogon/chemistry , Acyclic Monoterpenes/chemistry , Chromatography, GasРеферат
Objective To establish the method of fingerprint and content determination of multi-component for Xiangsha Yangwei pill by gas chromatography(GC).Methods The GC fingerprint of Xiangsha Yangwei pill was found,and the peak attribution was carried out.The contents of limonene,eucalyptol,camphor,borneol,bornyl acetate,patchouli alcohol,pogostone,and α-cyperone were determined.Results The fingerprint similarity of 56 batches of Xiangsha Yangwei pill were 0.33-0.99,28 common peaks were confirmed,and 14 known components were identified.Limonene,eucalyptol,camphor,borneol,bornyl acetate,patchouli alcohol,pogostone and α-cyperone showed good linearity within the determined ranges(14.30-286.08,24.52-490.44,16.14-322.88,9.40-187.95,15.39-307.83,25.78-515.60,19.95-398.90,and 24.87-497.30 μg·mL-1).The average recoveries were 101.20％,97.90％,93.97％,94.23％,102.94％,100.54％,99.16％,and 98.31％;with the RSDs were 2.41％,1.48％,1.65％,2.00％,1.93％,2.30％,2.07％,and 2.38％,respectively.The concentrations of eight components were 0.2-959.1,0.3-420.4,1.0-542.6,0.0-64.5,0.0-364.2,0.0-339.6,0.0-130.7,0.0-82.0 μg·g-1,respectively.Conclusion The fingerprint and multi-component determination method can be used for the quality control and evaluation of Xiangsha Yangwei pill.
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Objective To analyze the residual status,transfer behavior,and risk of paclobutrazole in the national mar-ket of Shenmai granules.Methods GC-MS/MS determined the residual amount of paclobutrazol in Shenmai granules,and ANOVA analyzed the distribution characteristics of sample residuals.The transfer rule of paclobutrazol from Ophiopogonis Radix to Shenmai granules was investigated by simulating the production process,and chronic exposure assessment was performed using the point evaluation model.Results The established method can accurately determine the residual amount of paclobutrazol in Shenmai granules.The residual amount of paclobutrazol in 85 batches of Shenmai granules ranged from 0.001 3 to 0.015 8 mg·kg-1,and there was a statistical difference in the residual amount among different enterprise samples.The transfer rate of paclobutrazol from decoction pieces to preparations was 29.8%.The chronic risk quotient(HQc)of paclobutrazol residues in Shenmai granules was 0.000 7%,far lower than 1.Conclusion There is a general presence of paclobutrazol residues in Shenmai granules.The risk assessment results show that the normal dosage of Shenmai granules does not pose an unacceptable risk to the general population.The residual distribution characteristics and process transfer rules can provide a reference for safety risk control in production enterprises.
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Objective To explore the antioxidant capacity of the volatile oil components of the Mongolian medicine Zhenbaowan and the mechanism of action in the treatment of rheumatoid arthritis(RA)by using bioinformatics technology,GC-MS technology,and antioxidant activity experiment.Methods The volatile oil in Zhenbaowan was extracted using water vapor distillation and the volatile oil components were qualitatively analyzed by GC-MS.Based on the results of GC-MS analysis,bioinfor-matics analysis was used to investigate the main components,key targets,and pathways of the volatile oil of Zhenbaowan in pre-venting and treating RA.Meanwhile,the antioxidant activity of the volatile oil was determined and analyzed using the 2,2-Diphen-yl-1-picrylhydrazyl(DPPH)method.Results A total of 115 volatile oil components were identified in Zhenbaowan,of which the top 48 components accounted for 97.66%of the total volatile oil content.Bioinformatics analysis revealed that Zhenbaowan can regulate signal transduction,inflammation,and protein phosphorylation through 147 RA-related targets,and intervene in signaling pathways such as PI3K-Akt,MAPK,and RAS.Molecular docking results showed that the seven main components of Zhenbaowan volatile oil can spontaneously bind to the five core targets.Antioxidant activity tests have proved that the volatile oil of Zhenbaowan has a more significant antioxidant capacity.Conclusion Using GC-MS high-throughput analysis technology combined with bioinformatic analysis and antioxidant activity test,the pharmacodynamic substances and mechanism of action of the volatile oil components of Zhenbaowan,a Mongolian medicine,in the treatment of RA are hypothesized.It provides a theoretical basis for the further study of the volatile oil components of Zhenbaowan.
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Objective To analyze the influence of different processing methods,including frying,ginger frying,and salt frying,on the volatile components of A.fructus.Methods The volatile components in different processed products of A.fructus were detected and analyzed by gas chromatography-mass spectrometry(GC-MS)based on multivariate statistical analysis.After OPLS-DA analysis,the different components were screened under the conditions of VIP＞1.5 and P＜0.05 and were qualitatively searched using the NIST 11 spectral library.Results A total of 49 different components were identified,with 14 components only changing in the seed mass and 22 components changing in the peel.The content of camphor could be significantly reduced in the seed mass after A.fructus was processed and the content of bornyl acetate significantly increased in the peel of frying A.fructus.Salt frying had a great influence on the alkanes in A.fructus,and ginger processing did not only increase the volatile components in ginger,which reflected the complexity of the processing mechanism.Conclusion At present,the specific processing mechanism is not clear,but the experimental results provide theoretical data for the "detoxification and efficiency enhancement" effect of A.fructus processing,reflecting the scientific nature of the processing,enriching the processing theory of A.fructus,and providing a reference for further in-depth research on the activity of different processed products of A.fructus.
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Objective To analyze the metabolic changes of myocardial tissue in rats under acute exposure to macleaya cordata by gas chromatography mass spectrometry(GC-MS),explore forensic identifications of its characteristic metabolites,and verify its toxicological mechanism in poisoning cases.Methods The rats in the exposure group were given 382 mg/kg macleaya extract solution by gavage,and the rats in the control group were given the same dose of solvent.The myocardial samples were analyzed by GC-MS,and pattern recognition was conducted through partial least squares discriminant analysis(PLSDA).The differential metabolites with characteristic changes were identified by variable importance projection(VIP value＞1)and Student's t test(P＜0.01).Results Compared with the control group,21 potential characteristic metabolites were identified.Through KEGG pathway enrichment analysis,it was found that these metabolites were mainly involved in the pathways of glycine,serine and threonine metabolism;pyruvate metabolism and glycerolipid metabolism.Conclusion Through the study of myocardial metabolism in rats exposed to macleaya cordata,we found the information on metabolites closely related to poisoning,which provides new insight and reference for studies on the mechanisms of macleaya cordata poisoning in the field of forensic medicine.
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Objective To analyze and identify the volatile constituents in different parts(flowers,stems and leaves)of Huai chrysanthemumin,and to lay a theoretical foundation for the comprehensive utilization for it.Methods The volatile oil in different parts of Huai chrysanthemumin were extracted by hydrodistillation,respectively.Their constituents were analyzed by gas chromatography-mass spectrometry(GC-MS).The compounds were identified by library search and literature screening.The relative percentage of each compound was obtained by the area normalization method.The differences in their chemical compositions were analyzed by Venn diagram,principal component analysis(PCA)and cluster heat map analysis.Results A total of 62 volatile chemical components were identified from different parts of Huai chrysanthemumin,including monoterpenes,sesquiterpenes,and their derivatives,as well as a small amount of aliphatic compounds.32,42 and 40 volatile components were detected from the flowers,stems and flowers,respectively.Furthermore 17 volatile components were shared by three parts,whereas 5,6 and 16 volatile components were unique to the flowers,stems and leaves,respectively.The results of stoichiometric analysis showed that both PCA and cluster heat map analysis could separate the flowers,stems and leaves,and their volatile components were different.Conclusion The types and contents of the volatile oil in the stems,leaves and flowers of Huai chrysanthemumin have certain variability,which provide a scientific basis for the further medicinal or industrial exploitation of different parts of Huai chrysanthemumin.
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Objective To determine the related substances in the pharmaceutical excipient triacetin by gas chromatography(GC).Methods Rtx-1701 and DB-1701 chromatographic column(30 m×0.25 mm,0.25 μm)was used,with nitrogen as the carrier gas,the flow rate was 1.5 mL/min,the inlet temperature was 200℃,the hydrogen flame ionization detector was used,the temperature of the measuring instrument was 250℃,and the program heating was used.Results Under this chromatographic condition,each substance could be effectively separated,and showed good linearity at 2-40 μg/mL(r>0.99).The recovery rates of acetic acid,glycerol,1-monoglyceryl acetate,1,2-diglyceryl acetate and 1,3-diglyceryl acetate were 100.7%(RSD=3.12%),95.1%(RSD=3.66%),99.43%(RSD=4.62%),103.66%(RSD=5.88%)and 103.15%(RSD=4.17%)(n=6),respectively.Conclusion This method has high accuracy and good reproducibility,which can be used for the determination of related substances in the triacetin,and provides a reference for the quality standard of triacetin.
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[Objective]To analyze the chemical components of the compound essential oil for mosquito repellent,which was composed of Menthae haplocalyx Briq.,Spirodela polyrrhiza(L.)Schleid,Acorus tatarinowii Schott and Rosmarinus offiicinalis L.,and to evaluate its repellent effect.[Methods]The chemical components of the compound mosquito repellent essential oil were analyzed by gas chromatography-mass spectrometer(GC-MS),and the repellent activity of the essential oil against adult Aedes albopictus was evaluated according to the"Efficacy Test and Evaluation of Space Repellent Products(Y-tube Method)".[Results]Fifty-eight main volatile components were identified,accounting for 98.28％of the total components of essential oil,eighteen terpenes(44.99％),nine alkenes(20.27％),five esters(14.07％),eight aromatic hydrocarbons(12.00％),seven alkanes(3.48％),nine alcohols(2.78％),two ketones(0.69％).The percent repellency(PR)of the compound mosquito repellent essential oil against Aedes albopictus was more than 90％on average.[Conclusion]There were many chemical components in the compound mosquito repellent essential oil.There may be a variety of chemical components such as menthol,menthone,α-pinene,etc,which had a repellent effect on Aedes albopictus,and the average repellent effect reached the A level.
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Background Propylene glycol monomethyl ether (PGME) is a widely used organic solvent. It exists in the form of two isomers in the workplace, which will cause adverse effects such as eye and upper respiratory tract irritation in workers. However, there is still a lack of standard detection methods for simultaneous detection of two isomers of PGME in China. Objective To establish a solvent desorption-gas chromatographic method for two isomers of PGME [1-methoxy-2-propanol (α-PGME), 2-methoxy-1-propanol (β-PGME)] in workplace air. Methods A method of solvent desorption-gas chromatography for α-PGME and β-PGME in workplace air were proposed. Air samples were collected with solvent desorption activated carbon tubes, desorbed using a desorption solution of dichloromethane/methanol (85:15), and then separated on a free fatty acid phase (FFAP) fused silica capillary chromatography column , detected with a flame ionization detector (FID), and quantified by peak area. Standard evaluation protocol was followed to obtain key indicators: standard curve, limit of detection, lower limit of quantification, relative standard deviation (RSD) that measures precision, and spiked recovery of sample solutions that measures accuracy. Desorption efficiency, sampling efficiency, and adsorption capacity tests were conducted, sample stability was evaluated using spiked activated carbon tube preservation test, and interference test was also assessed. The developed method was then applied to field air sample testing. Results In this method, using dichloromethane/methanol (85:15) as the sample desorption solution, the quantitative detection ranges of α-PGME and β-PGME were 0.95-923.0 μg·mL−1 and 0.97-912.0 μg·mL−1 with both correlation coefficients of 0.999 9, the method limits of detection were 0.28 µg·mL−1 and 0.29 µg·mL−1, and the lower limits of quantification were 0.95 µg·mL−1 and 0.97 µg·mL1, respectively. The lowest concentrations detected were both 0.19 mg·m−3, and the lowest concentrations quantified were 0.63 mg·m−3 and 0.65 mg·m−3, respectively, under the conditions of sampling volume of 1.5 L and the volume of desorption solution of 1.0 mL. The intra-batch precisions for α-PGME and β-PGME were 2.8%-4.9% and 2.8%-5.1%, the inter-batch precisions were 4.2%-5.7% and 4.5%-5.9%, the spiked recoveries were 98.8%-100.3% and 96.4%-102.9%, and the desorption efficiencies were 92.7%-97.3% and 92.2%-98.1%, respectively. The average sampling efficiency was 100%, and the samples could be stored at room temperature (25-30 ℃) for at least 7 d and at 4 ℃ for at least 15 d. The adsorption capacities of the activated carbon sampling tube for α-PGME and β-PGME were greater than 13.9 mg and 2.7 mg (100 mg of activated carbon adsorbent), respectively. Possible co-existing components in workplace did not interfere with the determination of α-PGME and β-PGME. The short-time exposure concentrations of α-PGME and β-PGME in the spray painting unit of an automobile manufacturing company were determined to be 18.69 mg·m−3 and 2.19 mg·m−3, and the time-weighted average concentrations were 6.03 mg·m−3 and 1.08 mg·m−3 respectively. Conclusion This method is accurate, precise and suitable for on-site monitoring of the two isomers of PGME in workplace air.
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A derivatizaton method combined with gas chromatography-mass spectrometry(GC-MS)was established for detection of isobutyl chloroformate(IBCF)residue in active pharmaceutical ingredient of agatroban.The extraction and derivatization reagents,derivatization time,qualitative and quantitative ions were selected and optimized,respectively.The possible mechanism of derivatization and characteristic fragment ions fragmentation were speculated.The agatroban samples were dissolved and extracted by methanol,and the residual IBCF was derived with methanol to generate methyl isobutyl carbonate(MIBCB).After 24 h static derivatization at room temperature,IBCF was completely transformed into MIBCB,which could be used to indirectly detect IBCF accurately.The results showed that the linearity of this method was good in the range of 25-500 ng/mL(R2=0.9999).The limit of detection(LOD,S/N=3)was 0.75 μg/g,and the limit of quantification(LOQ,S/N=10)was 2.50 μg/g.Good recoveries(95.2%-97.8%)and relative standard deviations(RSDs)less than 3.1%(n=6)were obtained from agatroban samples at three spiked levels of IBCF(2.50,25.00,50.00 μg/g),which showed good accuracy of this method.Good precision of detection results was obtained by different laboratory technicians at different times,the mean value of spiked sample solution(25.00 μg/g)was 24.28 μg/g,and the RSD was 2.1%(n=12).The durability was good,minor changes of detection conditions had little effect on the results.Under the original condition and conditions with initial column temperature±5℃,heating rate±2℃/min,column flow rate±0.1 mL/min,the IBCF content of spiked sample solution(25.00 μg/g)was detected,the mean value of detection results was 24.16 μg/g,and the RSD was 2.2%(n=7).Eight batches of agatroban samples from two manufacturers were detected using the established method,and the results showed that no IBCF residue was detected in any of these samples.The agatroban samples could be dissolved by methanol,and then the IBCF residue could be simultaneously extracted and derived with methanol as well.This detection method had the advantages of simple operation,high sensitivity,low matrix effect and accurate quantification,which provided a new effective method for detection of IBCF residue in agatroban.
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Objective To investigate the characteristic volatile organic compounds(VOCs)in exhaled breath and their diagnostic value in mice with early stage radiation injury.Methods The thermal desorption gas chromatography-mass spectrometry(TD-GC/MS)technique was used to analyze VOCs in exhaled breath of irradiated mice by 60Coγ-ray with 800 cGy.The characteristic VOCs in the early stage of radiation injury were identified,and a diagnostic model was established.Results The 30-day survival rate of mice was 4.2%.There were significant differences in characteristic VOCs at 7 hours after radiation injury,and thirty characteristic VOCs related to early-stage radiation injury were identified.The diagnostic value of differential metabolites in mice after irradiation was evaluated via the ROC curve,and the area under the ROC curve(AUC)of a single compound exceeded 0.8.The diagnostic model was constructed by screening 9 potential biomarkers of exhalation through Fisher discriminant analysis,and its sensitivity and specificity were close to 100%.Conclusion Analysis of VOCs in exhaled breath is expected to provide a non-invasive diagnostic method for early screening and diagnosis of radiation injury.
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ObjectiveTo establish a method for the determination of 1,1,1,2-tetrachloroethane (TeCA) and 1,1,2,2-TeCA in human urine using liquid-liquid extraction-gas chromatography. Methods The 5.0 mL urine sample was mixed with 2.0 g anhydrous sodium sulfate and 5.0 mL ethyl acetate, then vortexed mixing. The 1.0 mL extraction was separated by 100% dimethylpolysiloxane capillary gas chromatography column, detected by flame ionization detector, and quantified by an external standard method. Results The linear ranges of 1,1,1,2-TeCA and 1,1,2,2-TeCA were 0.250-50.750 mg/L, with both correlation coefficients of >0.999 9. The detection limit of 1,1,1,2-TeCA in urine was 0.020 mg/L, and the lower limit of quantification was 0.060 mg/L. The average recovery was 88.02%-101.32%, and the within-run and between-run relative standard deviations (RSDs) were 0.11%-0.47% and 0.39%-1.09%, respectively. The detection limit of 1,1,2,2-TeCA in urine was 0.050 mg/L, and the lower limit of quantification was 0.150 mg/L. The average recovery was 93.42%-101.32%, and the within-run and between-run RSDs were 0.28%-1.04% and 0.50%-1.03%, respectively. Both the 1,1,1,2-TeCA and 1,1,2,2-TeCA cannot be stored at room temperature. The 1,1,2,2-TeCA can be stored at 4 ℃ for at least three days. At -20 ℃, the 1,1,1,2-TeCA can only be stored for one day, while 1,1,2,2-TeCA can be stored for at least five days. Conclusion This method has high sensitivity, good specificity, simple sample pretreatment, and more intuitive and reliable results. It can be used to determine the level of 1,1,1,2-TeCA and 1,1,2,2-TeCA in urine of occupational population.
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Objective To establish a stable and reliable method for the determination of ethylene oxide residue,and to analyze ethylene oxide residue in multi components made of different materials involved in some medical devices,so as to provide references for sample selection and ethylene oxide residue detection of multi-component medical device kits.Methods A method for the determination of ethylene oxide residue of multi-component medical devices was developed using headspace-gas chromatography and DB-WAX column under the conditions of headspace extraction with equilibration at 80℃ for 20 min,and the weighing mass,linearity,limit of detection,limit of quantification,precision and recovery of the method were determined.Trials of the method were carried out on the items undergoing ethylene oxide sterilization,including disposable perineal care kit,disposable gynecological examination kit,disposable suture dressing kit,disposable debridement kit and the components contacting human body in the disposable dialysis kit,and the abilities of different materials of the components were analyzed in absorbing,retaining and releasing ethylene oxide.Results The method showed high linearity(r=0.999 8)in the range of ethylene oxide mass concentration from 0.4 to 16.0 μg/mL with a weighing mass of 1.00 g,which had the limit of detection being 0.11 μg/mL,the limit of quantification being 0.37 μg/mL and the relative standard deviations(RSDs)for the precision from 0.35％to 1.52％.The average recoveries of different spiked amounts of ethylene oxide in the three blank matrices ranged from 92.68％to 101.42％with the relative standard deviations(RSDs)from 2.46％to 7.59％,which all satisfied the detection requirements.The components made of rubber and acrylonitrile-butadiene-styrene copolymer(ABS)in multi-component medical device kits had the highest ethylene oxide residues,followed by the components made of wood,degreased cotton,polypropylene and polystyrene.Conclusion The method proposed gains advantages in easy operation and high specificity,quantification and reproducibility,which can be used for the determination of ethylene oxide residue in the multi-component medical device kit undergoing ethylene oxide sterilization.References are provided for sample selection of multi-component medical devices.[Chinese Medical Equipment Journal,2024,45(1):56-61]
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Traditional Chinese medicines (TCMs) possess a rich historical background, unique theoretical framework, remarkable therapeutic efficacy, and abundant resources. However, the modernization and internationalization of TCMs have faced significant obstacles due to their diverse ingredients and unknown mechanisms. To gain deeper insights into the phytochemicals and ensure the quality control of TCMs, there is an urgent need to enhance analytical techniques. Currently, two-dimensional (2D) chromatography, which incorporates two independent separation mechanisms, demonstrates superior separation capabilities compared to the traditional one-dimensional (1D) separation system when analyzing TCMs samples. Over the past decade, new techniques have been continuously developed to gain actionable insights from complex samples. This review presents the recent advancements in the application of multidimensional chromatography for the quality evaluation of TCMs, encompassing 2D-gas chromatography (GC), 2D-liquid chromatography (LC), as well as emerging three-dimensional (3D)-GC, 3D-LC, and their associated data-processing approaches. These studies highlight the promising potential of multidimensional chromatographic separation for future phytochemical analysis. Nevertheless, the increased separation capability has resulted in higher-order data sets and greater demands for data-processing tools. Considering that multidimensional chromatography is still a relatively nascent research field, further hardware enhancements and the implementation of chemometric methods are necessary to foster its robust development.
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ObjectiveTo explore the impact of Gegen Qinliantang（GQT） on the fecal short-chain fatty acids（SCFAs） metabolism in antibiotic-associated diarrhea（AAD） through targeted metabolomics. MethodA total of 240 SD rats were randomly divided into six groups（n=40， half male and half female）， including blank group， model group， bifidobiogen group（0.15 g·kg-1）， and GQT high-， medium-， and low-dose groups（10.08， 5.04， 2.52 g·kg-1）， except for the blank group， clindamycin（250 mg·kg-1） was given to all groups by gavage for modeling every day for 7 d. After successful modeling， each administered group was gavaged with the corresponding dose of the drug， and the blank and model groups were gavaged with an equal volume of normal saline solution， 1 time/d， for 14 d. At 0， 3， 7， 14 d after the drug intervention， eight rats were randomly selected from each group， respectively. Gas chromatography-time-of-flight mass spectrometry（GC-TOF-MS） was used to perform targeted metabolomic analysis of SCFAs in the feces of rats， and partial least squares-discriminant analysis（PLS-DA） was applied to compare the differences in metabolic profiles between groups at different treatment times， and to compare the changes in the contents of SCFAs in rat feces between groups. ResultPLS-DA results showed that the blank group could be clearly distinguishable from the model group， with GQT exhibiting a closer proximity to the blank group after 7 d of treatment. After further analyzing the composition of SCFAs， it was found that the proportion of acetic acid increased and the proportions of butyric acid， valeric acid， hexanoic acid and isovaleric acid decreased in the model group compared with the blank group. After the treatment with GQT， the proportions of butyric acid， isobutyric acid， valeric acid， and isovaleric acid increased， and the proportions of acetic acid， propionic acid and caproic acid decreased. Subsequent differential analysis revealed that GQT could significantly improve the content of butyric acid， and had a certain retrogressive effect on the contents of valeric acid and hexanoic acid. ConclusionThe medium dose group of GQT can improve the contents of SCFAs in AAD feces after 7 days of treatment， which may be related to the improvement of the composition ratio of SCFAs and the contents of butyric acid， valeric acid and caproic acid.
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ObjectiveTo discriminate the age of Arisaema Cum Bile， the combination of headspace solid-phase microextraction （HS-SPME） with gas chromatography-mass spectrometry （GC-MS） was applied to explore the differences of volatile components of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented Arisaema Cum Bile. MethodSamples with different fermentation durations were collected and HS-SPME-GC-MS technology was employed to detect the volatile components of each sample. The relative contents of detected volatile components were processed and analyzed by chemometrics methods such as principal component analysis （PCA）， hierarchical cluster analysis （HCA）， and partial least squares discriminant analysis （PLS-DA）. ResultThe results showed that 145 volatile components were identified. Among these volatile components， the relative contents of heterocyclic， alcohols， aldehydes and aromatics were high. PCA， HCA， and PLS-DA can effectively separate Arisaema Cum Bile with four different ages. Based on variable importance in projection （VIP） value > 1， 73 markers of differential volatile components were identified. The content of 2，6，11-trimethyldodecane and m-xylene in unfermented samples was the highest， and the content difference between them and those in fermented samples was significant （P<0.05）. 2，3-butanediol was detected only in 1-year samples， octane was detected only in 2-year samples， and ethyl heptanoate was detected only in 3-year samples. These components can be used as odor markers for Arisaema Cum Bile with different fermentation years. ConclusionThe identification method of volatile components of Arisaema Cum Bile was established by HS-SPME-GC-MS technology， which can realize the rapid identification of unfermented， 1-year fermented， 2-year fermented， and 3-year fermented samples， and provide a scientific basis for the standardization of processing technology and quality standards of Arisaema Cum Bile.
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ObjectiveTo screen the differential markers by analyzing volatile components in Dalbergia odorifera and its counterfeits， in order to provide reference for authentication of D. odorifera. MethodThe volatile components in D. odorifera and its counterfeits were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and the GC conditions were heated by procedure（the initial temperature of the column was 50 ℃， the retention time was 1 min， and then the temperature was raised to 300 ℃ at 10 ℃ for 10 min）， the carrier gas was helium， and the flow rate was 1.0 mL·min-1， the split ratio was 10∶1， and the injection volume was 1 mL. The MS conditions used electron bombardment ionization（EI） with the scanning range of m/z 35-550. The compound species were identified by database matching， the relative content of each component was calculated by the peak area normalization method， and principal component analysis（PCA）， orthogonal partial least squares-discrimination analysis（OPLS-DA） and cluster analysis were performed on the detection results by SIMCA 14.1 software， and the differential components of D. odorifera and its counterfeits were screened out according to the variable importance in the projection（VIP） value>2 and P<0.05. ResultA total of 26， 17， 8， 22， 24 and 7 volatile components were identified from D. odorifera， D. bariensis， D. latifolia， D. benthamii， D. pinnata and D. cochinchinensis， respectively. Among them， there were 11 unique volatile components of D. odorifera， 6 unique volatile components of D. bariensis， 3 unique volatile components of D. latifolia， 6 unique volatile components of D. benthamii， 8 unique volatile components of D. pinnata， 4 unique volatile components of D. cochinchinensis. The PCA results showed that， except for D. latifolia and D. cochinchinensis， which could not be clearly distinguished， D. odorifera and other counterfeits could be distributed in a certain area， respectively. The OPLS-DA results showed that D. odorifera and its five counterfeits were clustered into one group each， indicating significant differences in volatile components between D. odorifera and its counterfeits. Finally， a total of 31 differential markers of volatile components between D. odoriferae and its counterfeits were screened. ConclusionHS-GC-MS combined with SIMCA 14.1 software can systematically elucidate the volatile differential components between D. odorifera and its counterfeits， which is suitable for rapid identification of them.
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Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min−1 for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min−1 for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol−1, the limits of quantification were in the range of 0.02-0.44 nmol·mol−1, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol−1. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.
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ObjectiveTo investigate the mechanism of Atractylodis Macrocephalae Rhizoma（AMR） in the treatment of slow-transmission constipation（STC） by observing the effects of AMR on short-chain fatty acids and intestinal barries in STC mice. MethodForty-eight male KM mice were randomly divided into blank group， model group， AMR low-， medium-， high-dose groups（2.5， 5， 10 g·kg-1） and mosapride group（2.5 mg·kg-1）. Except for the blank group， all groups were gavaged with loperamide suspension（5 mg·kg-1） twice daily for 14 d to construct the STC mouse model. At the same time， each drug administration group was given the corresponding drug by gavage for consecutive 14 d， the blank and model groups were gavaged with equal volume of distilled water. The effects of the treatment of AMR on body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice were observed， the pathological changes of mouse colon were observed by hematoxylin-eosin（HE） staining and periodic acid-Schiff（PAS） staining， the levels of gastrin（GAS） and motilin（MTL） in serum were detected by enzyme-linked immunosorbent assay（ELISA）， gas chromatography-mass spectrometry（GC-MS） was used to detect the contents of short-chain fatty acids（SCFAs） in mouse feces， real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） and Western blot were used to determine the mRNA and protein expression levels of zonula occludens-1（ZO-1）， Occludin， and Claudin-1 in the colon of mice. ResultCompared with the blank group， the body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice in the model group were significantly decreased（P<0.05， P<0.01）， the arrangement of colonic tissues was disordered， and the number of goblet cells was reduced， the levels of GAS and MTL in serum were significantly decreased（P<0.01）， and the levels of SCFAs in the feces were on a decreasing trend， with the contents of acetic acid， propionic acid， butyric acid， isobutyric acid and valeric acid were significantly decreased（P<0.05， P<0.01）， the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colonic tissues were significantly decreased（P<0.01）. The above results suggested that STC mouse model was successfully constructed. Compared with the model group， the body mass， defecation frequency， fecal water content and intestinal propulsion rate of mice in AMP administration groups all increased significantly（P<0.05， P<0.01）， the mucosal layer of the colonic tissues was structurally intact without obvious damage， and the number of goblet cells increased， serum levels of GAS and MTL were significantly increased（P<0.01）， the contents of SCFAs in the feces were all on a rising trend， with the contents of acetic， propionic， butyric and isobutyric acids rising significantly（P<0.05， P<0.01）， the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colonic tissues were significantly increased（P<0.05， P<0.01）. ConclusionAMR is able to improve the constipation symptoms in STC mice， and its mechanism may be related to increasing the contents of SCFAs in the intestine as well as promoting the mRNA and protein expression levels of ZO-1， Occludin and Claudin-1 in the colon.