衍生气相色谱法在环境监测中的应用分析

在社会快速发展的同时,环境问题也变得越来越严重,对人们的日常生活带来一定程度的影响。就目前情况看来,环境监测在保护自然环境当中占据着非常重要的地位,该工作不仅能够及时发现环境问题的存在,而且还能够第一时间采取措施来对问题进行处理,不过部分工作人员还在沿用传统的监测方法和技术,这样就会导致监测结果与实际情况不相符合。所以,相关部门在开展环境监测过程中要对衍生气相色谱法进行充分应用,这样才可以进一步提高监测结果的准确性和科学性。

Chemical composition and anti-MRSA activity of the essential oil from Chinese eaglewood

To analyze the constituents of essential oil from Chinese eaglewood [resinous wood of Aquilaria sinensis （Lour.） Gilg] and its anti-methicillin-resistant Staphylococcus aureus （MRSA） activity. The essential oil was extracted by water-steam distillation and analyzed by GC/MS method. The relative contents of the compounds were determined by normalization. The compounds were characterized by NIST05 and WILEY275L database matching and comparison of their MS spectra with those of literature data. Antibacterial activity of the oil was assayed by the filter paper disc agar diffusion method. The oil showed significant antibacterial activity against MRSA. Sixty-six chromatographic peaks were detected, among them thirty compounds comprising 59.80% of the total essential oil were characterized. Twenty-six compounds comprising 54.26% of the oil were identified as sesquiterpenes. β-Agarofuran （8.96%）, kusunol （7.82%）, （-）-jinkoh-eremol （5.04%）, agarospirol （4.53%）, baimuxifuranic acid （4.09%） were the major sesquiterpenes. Four nor-sesquiterpenes and some other sesquiterpenes, such as 10-epi-γ-eudesmol, α-agarofuran, epi-ligulyl oxide, etc. were detected in Chinese eaglewood oil for the first time. This is the first report about anti-MRSA activity of Chinese eaglewood oil from A. sinensis.

Analysis of Volatile Constituents in Lonicera japonica Thunb. from Different Origins by GC-MS

[Objective] This study aimed to analyze the volatile constituents in Lonicera japonica Thunb. from different origins. [Method] HP-5MS capillary columns were used and column temperature was controlled by a program. MS analysis was performed with EI and quadruple mass analyzer. The volatile constituents in L. japonica Thunb. were identified by NIST02 and Wiley275 libraries, and their relative contents were determined with chromatographic peak area normalization method. [Result] According to GC-MS total ion-current chromatograms, 35 volatile constituents were identified in L. japonica Thunb. from Guangxi Zhuang Autonomous Region, mainly including methyl linolenate, n-hexadecanoic acid and ζ-muurolene; 18 volatile constituents were identified in L. japonica Thunb. from Hunan Province, mainly including n-hexadecanoic acid, linoleic acid and α-curcumene. [Conclusion] Main volatile constituents in L. japonica Thunb. from two different origins varied significantly.

Analysis for the Volatile Secondary Metabolites of Mortierella alpina

[ Objective] The study was to investigate the volatile components of secondary metabolites from M. alpine producing arachidonic acid and explore the changes in its metabolic pathway. [ Method] The air above M. alpine broth was extracted by solid-phase microextraction（SPME） during the post-exponential phase of growth and analyzed by GC-MS. [Result] 13 compounds were identified, 12 of which were sesquiterpenes with C15H24 formula and accounting for 99.62% of the complete compounds. Thujopsene-（ 12）, α-Guaiene and Aristolene were three most sesquiterpenes accounting for 10.66%, 33.69% and 34.85% of total content respectively. It can be sufficiently certified that sesquiterpene metabolic pathway existing in M. alpine. [ Coclusion] Metabolic flux of sesquiterpene pathway increased to improve its mass accumulation, because one or several key enzyme genes mutation in isoprene or sesquiterpene pathway enhanced their activities during induction of mutation from initial strain.

Chemical Compositions of Volatile Oil from Fruiting Body of Armillaria luteo-virens

The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.

Leaf Volatiles Induced by Mechanical Damage from Diverse Taxonomic Tree Species

Plant volatiles induced by wounding play key roles in plant-insect and plant-plant interactions. To deeply understand the mechanism of their induction by wounding and their functions in interplant communications, four diverse tree species: ashleaf maples ( Acer negundo L.), hankow willow (Salix matsudana Koidz.), Chinese white poplar ( Populus tomentosa Carr.) and poplar opera 8277 (P. simonii x P. pyramibalis cv.), were used as materials. The blends of volatiles collected after damage were detected with GCMS. Most of the induced compounds reach high concentrations in 5 h. They are acyclic monoterpenes, fatty acid derivatives, and aromatic compounds. To authors' knowledge, dimethyl adipate, diisobutyl succinate and benthothiazole have never been reported in previous herbivore insect-plant systems, After being damaged 2 h, green leaf volatiles were released in large amount. The repellents were detected in higher concentration after 24 h. The time of releasing is different within different species, but many kinds of volatiles widely existed in different trees. There were some difference among species. Health ashleaf maple released more terpenoids, but poplars and willow produced more aromatic compounds.

石蜡中微量低碳烃类的组成分析

利用静态顶空法捕集石蜡样品中的残留低碳烃类。用PONA色谱柱共分离出26种化合物，采用气相色谱法对低碳烃类的组成进行定性，最后用所相相色谱/原子发射光谱用仪，外标法测定了各组分含量。

Analysis of Volatile Constituents in Bamboo Leaves Using HS-GC/MS

[Objective] This study aimed to analyze the volatile constituents in bamboo leaves. [Method] The volatile compositions in bamboo leaves were analyzed by headspace-gas chromatography-mass spectrometry （HS-GC/MS）, and identified by searching their mass spectra in NIST database. The relative percentages of them were calculated by the GC peak areas. [Result] Fifty-three chemical constituents in bamboo leaves were separated. Among them, the main components were alcohols, ketones and aldehydes, and these compounds contained unsaturated bonds. [Con- clusion] HS-GC/MS was simple and less sample-demanding and can be used for rapid analysis of volatile constituents in bamboo leaves and provide scientific basis for further research and development of bamboo leaves.

简述几种新型的饲料检测技术

饲料检测技术具有较强的实用性价值,在饲料检测中扮演着重要角色,因此本文对几种饲料检测技术的应用原理进行了介绍以便更好地选择适合的检测技术,提高检测的准确率和检测效率。1光学分析技术1.1原子吸收光谱法该法是光学分析技术中的一种,能够对目标物内元素的浓度进行检测,具有精准和快速等特点,具有良好的应用效果。此项技术,不仅可以对目标物内的铜元素进行总含量测定,还能借助火焰原子吸收光谱法来对镉元素的质量分数进行分析判断,从而为饲料产品的品质提供保障。该技术的不足之处是对真空紫外环境下的元素检测的准确性不是很好,使用不当还会干扰曲线分析。

Experimental investigation on combustion and unregulated emission characteristics of butanol-isomer/gasoline blends

Effects of butanol isomers on characteristics of combustion and emission were studied on PFI SI engine. Experiments were operated under the condition of 3 and 5 bar brake mean effective pressure (BMEP) engine loads and different equivalence ratios (φ=0.83-1.25) with engine speed of 1200 r/min using blends made of 70 vol.% gasoline and 30 vol.% butanol isomers (N30, S30, I30 and T30). The results indicated that compared with gasoline, all butanol isomer blends have higher cylinder pressure. N30 has the highest and most advanced peak pressure, and T30 shows a higher brake specific fuel consumption (BSFC) and lower brake thermal efficiency (BTE). N30 presents a lower UHC emissions and I30 has slightly higher CO emissions than other blends. For unregulated emissions, compared with gasoline, butanol isomer blends have higher acetaldehyde, and N30 produces a higher emission of 1,3-butadiene than other blends. A reduction in benzene, toluene, ethylbenzene and xylene (BTEX) has been found with butanol isomer blends.

Rapid and simultaneous determination of ten off-flavor compounds in water by headspace solid phase microextraction and gas chromatography-mass spectrometry

A simple and sensitive analytical procedure for the determination of multi-component compounds in water samples was developed and optimized using the headspace solid-phase microextraction(HSSPME) coupled with gas chromatography-mass spectrometry(GC-MS). Ten off-flavor compounds, including geosmin(GSM), 2-methylisoborneol(2-MIB), 2-isopropyl-3-methoxypyrazine(IPMP), 2-isobutyl-3-methoxypyrazine(IBMP), β-ionone, trans-2,cis-6-nonadienal(NDE), 2,3,4-trichloroanisole(2,3,4-TCA), 2,3,6-trichroloanisole(2,3,6-TCA), 2,4,6-trichloroanisole(2,4,6-TCA), and 2,4,6-tribromoanisole(2,4,6-TBA) were used as the target analytes. The optimization of extraction parameters including fibers types, extraction time, extraction temperature, stirring rate, sample volume, and ionic strength was carried out through the univariate approach. Ten off-flavor compounds were quantified within 50 min under the optimal conditions. Calibration curves with good linearity(r^2=0.990-0.998) were obtained in the range 1.0/2.0-100 ng/L, while the limits of detection for all compounds were lower than or close to the odor threshold concentration. Furthermore, the proposed method was applied to analyzing and determining the off-flavor compounds in real water samples from water-treatment plants.

A Metabolomics Study of the Volatile Oil from Prunella vulgaris L.on Pelvic Inflammatory Disease

Objective Pelvic inflammatory disease(PID)is one of the most common gynaecological diseases.Here,this thesis aims to investigate the therapeutic effects of Prunella vulgaris L.oil on the PID by using metabolomics based on gas chromatographymass spectrometry(GC-MS)to address this challenge.Methods First,measurements of pro-inflammatory cytokines and histological analysis of the uterus were conducted to validate the successful generation of a PID rat model.Furthermore,the volatile oil from Prunella vulgaris L.was administered to treat PID rats.Serum samples were collected before and after treatment and analyzed by GC-MS to generate metabolite profiles for each sample.The information generated from the qualitative and quantitative analysis of these metabolites was applied to distinguish between the PID model and normal control groups.Results Some metabolites,such as acetic acid,succinic acid,glyceric acid,(R*,S*)-3,4-dihydroxybutanoic acid,3-hydroxyphenylacetic acid,D-ribose and myo-inositol showed a higher contribution in the classification model;thus,they can be considered as potential biomarkers.Furthermore,the therapeutic effect of the volatile oil extracted from Prunella vulgaris L.could also be visualized using GC-MS-based metabolomics.Conclusions The results show that metabolomics studies are invaluable for disease diagnosis and therapeutic effect estimation.

Comparative analysis of volatile constituents between herbal pair flos lonicerae-caulis lonicerae and its single herbs

Gas chromatography-mass spectrometry(GC-MS) and the chemometric resolution method(alternative moving window factor analysis,AMWFA) were used for comparative analysis of volatile constituents in herbal pair(HP) flos lonicerae-caulis lonicerae(FL-CL) and its single herbs.The temperature-programmed retention index(PTRI) was also employed for the identification of compounds.In total,44,39,and 50 volatile chemical components in volatile oil of FL,CL and HP FL-CL were separately determined qualitatively and quantitatively,accounting for 87.22%,94.54% and 90.08% total contents of volatile oil of FL,CL and HP FL-CL,respectively.The results show that there are 32 common volatile constituents between HP FL-CL and single herb FL,33 common volatile constituents between HP FL-CL and single herb CL,and 10 new constituents in the volatile oil of HP FL-CL.

Mechanism of volatile oil from Chuanxiong(Chuanxiong Rhizoma)-Suhexiang(Styrax)-Bingpian(Borneolum)in treating angina pectoris based on network pharmacology and its protective effects on myocardial damage in rats

Objective To explore the pharmacodynamic material basis and mechanism of action of volatile oil from Chuanxiong(Chuanxiong Rhizoma)-Suhexiang(Styrax)-Bingpian(Borneolum)(hereinafter referred to as C-S-B volatile oil)in treating angina pectoris based on network pharmacology and to detect its protective effects against rat myocardial damage.Methods Gas chromatography-mass spectrometry(GC-MS)was used to determine the constituents of volatile oils from Chuanxiong(Chuanxiong Rhizoma),Suhexiang(Styrax),and Bingpian(Borneolum),and the targets of the three main constituents were found predicted and screened using the PharmMapper server,and Gene Cards and Coo LGe N databases.The STRING database and Cytoscape software were used to draw the protein-protein interaction(PPI)network,RStudio software was used to analyze Gene Ontology(GO)and Kyoto Encyclopedia of Genome and Genome(KEGG)pathways,and Cytoscape software was used to construct the component-target-pathwaydisease network.The rat model of myocardial injury was established by intraperitoneal injection of a large dose of isoprenaline hydrochloride.After continuous intervention with C-S-B volatile oil for 14 d,the ejection fraction(EF)and short axis shortening rate(FS)of the left ventricle were detected.The indices of myocardial damage were detected after hematoxylin-eosin(HE)staining.Results Fifteen volatile oil components from the C-S-B formula were identified.There are 470 targets of these volatile oil components and 401 angina-related genes.There are 28 core targets,including CHRM4,ADRA1 A,FGFR1,CHRM2,CYP2 A6,CHRM5,CHRM1,CHRM3,HDAC2,and MPO,etc..The results of the KEGG analysis indicated that the C-S-B formula probably interferes with the following pathways:neuroactive ligand-receptor interactions,calcium signaling,cytochrome P450 metabolism of heteropoietin,among others.The results of animal experiments showed that the C-S-B formula essential oil could significantly improve the following myocardial indices in rats with myocardial injury:EF,FS,left ventricular end-systolic diameter(LVIDs),left ventricular end-diastolic diameter(LVIDd),and stroke volume(SV),and all the differences were statistically significant(P<0.01).Conclusion The mechanism of action of volatile oil components in the C-S-B formula in treating angina pectoris was analyzed using multi-component,multi-target and multi-pathway systems,which has laid a foundation for further revealing its mechanism of action.Animal experiments have shown that the volatile oil of the C-S-B formula can improve EF,FS,and other indices of myocardial damage in a rat model,thus relieving myocardial damage caused by heart hyperactivity,improving cardiac function,and protecting against myocardial damage.

Composition of Trans-anethol and Other Aromatic Volatiles in Anisated Alcoholic Beverages by Head-Space GC-MS Chromatography

Aniseed distillates, like ouzo in Greece, raki in Turkey, pastis in France, and arak in Syria, are very popular in Mediterranean countries. This flavoured alcoholic beverage is produced by extraction and distillation of fermented grape pomaces with herbal seeds from aromatic plants like Pimpinella anisum L., Foeniculum vulgate, Illicium verum and other plants which are also characterized by the presence of congeners which arise during fermentation process. Trans-anethol and its isomer cis-anethol are the main volatiles and are responsible for aroma properties of these traditional aniseed distillates. The aim of this research work was to find the concentration of special aromatic agent, trans-anethol and cis-anethol and also the major aromatic substances which are responsible for the aromatic quality. The majority of their identified components are isolated by extraction and distillation from different commercial brands and homemade samples. The constituents were identified by GC-MS （gas chromatography-mass spectometry） in this traditional spirit. The major constituents in distilled ouzo extract were also trans-anethol.

Chemical component and antimicrobial activity of volatile oil of Calycopteris floribunda

The volatile oil of leaves and barks of Calycopteris floribunda was examined by gas chromatography-mass spectrometry (GC-MS). 52 volatile chemical components in leaves were identified. The antimicrobial assay of oils in the leaves and barks was carried out by disk diffusion method in vitro. The major components (mass fraction) in leaves are caryophyllene oxide (13.79%),n-hexadecanoic acid (11.91%) and β-caryophyllene (10.45%). Ten constituents are identified accounting for about 99.98% of the total volatile oil in the bark. Among these components,n-hexadecanoic acid (59.18%),linolic acid (12.70%) and butyl octyl phthalate (8.21%) are the major constituents. The oils exhibit strong antimicrobial activity and display more potent against bacteria than fungi.

Influence of the post-fermentation by four Aspergillus strains on the aroma of pu-erh tea

Aroma is one of the most important factors for the flavor, taste, and quality of pu-erh tea, and the post-fermentation process has an important influence on the aroma of pu-erh tea. In the present study, the influence of fungi fermentation on the flavor of pu-erh tea was investigated and compared. Volatile compounds from pu-erh tea fermented by four Aspergillus strains, including A. niger, A. oryzae, /1. awamori, and A. glaueus, were extracted and analyzed using ultrasound-assisted extraction-dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry （UAE-DLLME-GC-MS）, and a total of 63 volatile compounds were identified. In comparison with the sun-dried green tea, fermented pu-erh tea contained high levels of methoxyphenolic compounds, such as 1,2,3-trimethoxybenzene, which was the most abundant one. Our results confirmed that the characteristic methoxyphenolic compounds were produced by the activity of Aspergillus during the post-fermentation process, and A. niger and A. awamori were the most important strains for the formation of aroma quality of pu-erh tea.

Chemical composition and antimicrobial activities of the essential oil of Aconitum tanguticum

The composition and antimicrobial activities of the essential oil of Aconitum tanguticum from the southern part of Gansu Province of China were investigated. The essential oil of aerial parts was obtained by hydrodistillation with a 0.7% （v/w） yield. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry （GC-MS） method. Thirty-five compounds were characterized in the oil, which were mainly monoterpenoids （41.7%） and sequiterpenoids （12.7%）. The main compounds in the oil were （-）-tran-pinecarvyl acetate （15.6%）, heptane （14.88%）, cineole （6.82%）, 3-pinanone （3.64%）, pinocamphone （3.34%）, cadinol （2.93%）, and cubenol （2.33%）. These compounds are identified for the first time in Aconitum tanguticum. The antimicrobial activities of the oil were evaluated against 9 bacteria strains, 1 yeast strain and 3 fungi strains using agar diffusion and broth microdilution methods. It showed strong inhibition against Fusarium semitectum and methicillin-resistant Staphlococcus aureus, low activity against Escheriehia eoli, but no effect against Epidermophyton floccosum. Its MIC values ranged from 0.125 5.000 mg/mL. Thirty-five compounds are newly identified in Aconitum tanguticum.

Comparison of volatile constituents in two types of mugwort leaves(produced in Qichun and Nanyang) using the headspace GC-MS

Objective： To compare the volatile constituents in mugwort leaves produced in Qichun, Hubei Province and Nanyang, Henan Province. Methods： The volatile constituents were extracted using headspace heating and analyzed using gas chromatography-mass spectrometry （GC-MS）. Then a qualitative analysis was made according to the standard database provided by the National Institute of Standards and Technology （NIST） and the relative contents of each constituent were calculated using the peak area normalization method. Results： A total of 59 compounds were identified from the mugwort leaves from Qichun and 51 compounds were identified from the mugwort leaves from Nanyang. These mainly include monoterpenoids, sesquiterpenoids, C^HvOz and other compounds involving the aldehyde, ketone, alkane and benzene. The mugwort leaves from Qichun and Nanyang share 32 common volatile constituents. The chromatographic peak area of identified compounds accounting for 96.38% of GC-MS total chromatographic peak areain Qichun mugwort leaves, versus 95.54% of that in Nanyang mugwort leaves. Conclusion： The headspace heating extraction combined with GC-MS technology can evidently display similarities and differences of volatile constituents in mugwort leaves produced in different areas and thus provide scientific basis for the quality and screening of mugwort leaves.

Organic composition of gasoline and its potential effects on air pollution in North China

When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the fuel can escape the vehicle through evaporation. Changes in alkanes, olefins and aromatics each affect emissions differently, which could complicate control strategies for air pollution. In this study, we collected 31 gasoline samples over five provinces and cities(Beijing, Tianjin, Hebei, Shandong, and Shaanxi) in North China between 2012 and 2013. The organic composition of the gasoline samples was analyzed using the gas chromatography-mass spectrometry(GC-MS) method, and the aniline compounds were analyzed by solvent extraction and the GC-MS method. The ratios of alkanes, aromatics, olefins and other organic compounds in gasoline were 40.6%, 38.1%, 12.9% and 8.4%, respectively. The aromatic and benzene exceedances were 15 and 8 based on the China's gasoline standards(III), and they accounted for 48.4% and 25.8% of all the gasoline samples, respectively. Strong carcinogen aniline compounds were detected in all 31 samples, and the content of aniline compounds in 3 samples exceeded 1%. The high proportion of aromatics and olefins in the gasoline increased the emissions of carbon monoxide(CO) and toxics, as well as the atmospheric photochemical reactivity of exhaust emissions, which could hasten the formation of secondary pollutants. Our results are helpful for redefining government strategies to control air pollution in North China and relevant for developing new refining technology throughout China.