阔叶箬竹叶和箬竹叶中挥发油的提取及成分分析

采用水蒸气蒸馏法分别提取阔叶箬竹叶和箬竹叶中的挥发油,用乙醚作溶剂进行多次萃取,利用气相色谱-质谱(GC-MS)联用分析二者的化学成分并进行比较。从阔叶箬竹叶提取的挥发油中共鉴定出37种化合物,主要成分为叶醇、1-己醇、苯甲醇、己醛、2-乙基呋喃、β-紫罗兰酮等。从箬竹叶提取的挥发油中共鉴定出49种化合物,主要成分为叶醇、苯甲醇、β-紫罗兰酮、2-己烯醛、苯乙醇、2-甲氧基-4-乙烯基苯酚、2-乙基呋喃等。两种箬叶挥发油中相对含量最高的成分都为叶醇,都含有酮、醛、醇、酚、酯类化合物,且酮、醛、醇的含量明显高于其他成分。     

顶空固相微萃取-气相色谱-质谱法分析莪术的挥发油成分

采用顶空固相微萃取-气相色谱-质谱法分离和鉴定莪术挥发油成分,用归一化测定其相对含量。共分离出64个组分,鉴定出57种化合物,其含量占总挥发油组分峰面积98.02%。主要挥发成分及其含量为β-榄香稀(18.73%)、β-榄烯酮(11.03%)、莪术二酮(8.47%)、γ-榄香稀(6.79%)。     

气相色谱-质谱法测定艾叶挥发油中化学成分

采用水蒸气蒸馏法提取艾叶的挥发油,用气相色谱-质谱法分离和鉴定挥发油成分,并用归一化法测定其相对含量。共分离出76个组分,鉴定出59种化合物。其含量占总挥发油组分峰面积的94.3%。贵州遵义产艾叶主要挥发油成分及其含量为1,8-桉叶油素(22.19%)、樟脑(10.39%)、绿花白千层醇(6.57%)、蒿醇(4.95%)、L-龙脑(4.88%)、α-松油烯(3.98%)、蒿酮(3.44%)、顺式桧烯水合物(3.36%)、4-松油醇(2.68%)、菊油环酮(2.51%)、β-崖柏酮(2.41%)、1-松油醇(2.32%)和丁香酚(2.26%)等。     

静态顶空-气相色谱-质谱法测定4种牡丹花的挥发性成分

采用静态顶空-气相色谱-质谱法分离和鉴定4个品种牡丹花的挥发性成分,并用归一化法测定其相对含量。共鉴定出30种化合物,主要为醇、酯、萜烯、醚和醛等物质,不同品种挥发性成分的种类和含量存在较大差异。4种牡丹花的共有物质是叶醇、正十二烷、苯乙醇和乙酸橙花酯等。苯乙醇是藏枝红和红珠女中含量最高的成分,分别高达54.05%和49.99%,而墨楼争辉和李园红中含量最高的是乙酸橙花酯,分别为34.07%和20.06%。     

气相色谱-质谱法测定废旧印刷线路板真空热解油的组分

采用气相色谱-质谱法从废旧印刷线路板的真空热解油中分离并确认出21种化合物,与红外光谱分析所推断的结果相一致,并用峰面积归一化法得出各化合物的相对含量.结果表明:热解油组分经过DB-5非极性柱可以实现分离,油中相对含量较高的主要成分为苯酚(30.17%)、对异丙基苯酚(10.29%)、对苯基苯酚(13.93%)、对异丙烯基苯酚(8.21%)和双酚A(15.46%).     

气相色谱-质谱法测定姜黄挥发油化学成分

采用水蒸气蒸馏法提取姜黄挥发油,用气相色谱－质谱联用技术分离和鉴定姜黄挥发油的化学成分。经计算机ＮＢＳ谱库检索,发现姜黄挥发油中至少有１５个峰,鉴定出α－姜黄烯、α－姜烯、桉叶油素和球姜酮等１５种组分;另外还有１－（３－环戊基醛）－２,４－二甲基苯、β－倍半水芹烯、大根香叶酮、大根香叶烷、顺双环［３,３,１］酮－２－烯－９－醇等成分。姜黄挥发油中主要成分为α－姜黄烯。     

气相色谱法测定费托合成水相产物中的低碳醇、醛、酮化合物

建立了铁基催化剂费托合成反应水相产物中低碳(C₁~C₈)醇、醛、酮的气相色谱测定方法.对色谱分离条件进行了优化,确立了以乙醇为基准物质并结合各组分校正因子的定量方法;考察了方法的精密度和准确度,并对费托合成反应水相产物样品进行了测定.结果表明,乙醇在不同的含量范围内呈现良好的线性关系,相关系数均大于0.99.费托合成水相产物中的加标回收率在93.4%~109.6%之间,准确性可以满足实际分析的需要.实际费托合成水相产物的分析结果表明,费托合成水相产物中主要的低碳醇、醛、酮的总质量分数约为3%~12%,乙醇含量最高(约为1.7%~7.3%),且正构醇、异构醇和醛酮类化合物所占的总比率依次降低.该方法简单、快速,对费托合成水相产物中重要组分的分析有重要意义.     

基于代谢组学方法的混合香精香料差异性物质鉴定与品质分析

使用气相色谱-质谱和代谢组学分析方法,研究了4种混合香精香料的多批次样本中的特征性和差异性物质,并对样本的品质一致性进行分析评价。从A、B、C、D 4种混合香精香料中分别鉴定出49、32、48、39种物质,其中乙酸乙酯、乙酰丙酸乙酯、异戊酸异戊酯、麦芽酚、二丙二醇、乙酸、4-氧代戊酸及5-羟甲基-2-呋喃甲醛8种物质是共有的主要风味组分。A与C型样本风味成分较为相似,果香与花香特征的酯类物质含量最为丰富,B型中具有酸香特征的酸类物质含量较高,D型中酮类致香物质最多。主成分分析与偏最小二乘判别分析能够识别混合香精香料中的特征性与差异性物质。根据变量投影重要性及统计结果筛选出的苹果酸二乙酯、反式-橙花叔醇、乙基麦芽酚等40种物质可用于4种香精香料的品质判断。不同类型样本的物质组成差异明显,同类型不同批次样本间特征物质的质量波动较小、品质一致性较好。     

广东土牛膝超临界流体萃取物的 GC-MS分析

采用GC－MS技术,对广东土牛膝的超临界流体萃取物中的化学成分进行了分析。气相色谱分离出77种组分,鉴定出其中32种化合物,主要为萜类物质（大部分为倍半萜）、有机酸及其酯类、酚类等化合物。     

固相微萃取-气相色谱-质谱法分析香樟籽挥发性成分

采用固相微萃取-气相色谱-质谱法分离和鉴定香樟籽的挥发性成分,用归一化法测定其相对含量。共分离出76种组分,鉴定出47种化合物,其含量占总挥发性成分的97.4%。主要挥发成分为樟脑(57.89%)、柠檬烯(12.68%)、α-蒎烯(4.42%)、莰烯(2.69%)、香橙烯(2.34%)、伞花烃(2.26%)及β-蒎烯(2.12%)。     

Water-soluble constituents of cumin: monoterpenoid glucosides

From the water-soluble portion of the methanol extract of cumin (fruit of Cuminum cyminum L.), which has been used as a spice and medicine since antiquity, sixteen monoterpenoid glucosides, including twelve new compounds, were isolated. Their structures were clarified by spectral investigation.     

Chemical composition and antimicrobial activity of cumin oil (Cuminum cyminum, Apiaceae)

Cumin oil samples (Cuminum cyminum L.) from four different geographical origins were analyzed using GC-MS and GC-FID for their qualitative and quantitative composition. The major compounds in all cumin oils were the monoterpenes beta-pinene, p-cymene and gamma-terpinene and the terpenoid aldehydes cuminic aldehyde and the isomeric menthadien carboxaldehydes. All essential oils, and cuminic aldehyde, were tested, using agar diffusion and serial dilution methods, against different Gram-positive and Gram-negative bacteria isolated from different sources of food (pork fillet, minced meat and sausages) and clinical isolates, as well as three different Candida albicans isolates. All cumin oils and cuminic aldehyde exhibited a considerable inhibitory effect against all the organisms tested, except Pseudomonas spp.     

Headspace single drop microextraction coupled with microwave extraction of essential oil from plant materials

Headspace single drop microextraction (HS-SDME) coupled with microwave extraction (ME) was developed and applied to the extraction of the essential oil from dried Syzygium aromaticum (L.) Merr. et Perry and Cuminum cyminum L. The operational parameters, such as microdrop volume, microwave absorption medium (MAM), extraction time, and microwave power were optimized. Ten microliters of decane was used as the microextraction solvent. Ionic liquid and carbonyl iron powder were used as MAM. The extraction time was less than 7 min at the microwave power of 440 W. The proposed method was compared with hydrodistillation (HD). There were no obvious differences in the constituents of essential oils obtained by the two methods.     

Phytotherapeutic inhibition of supragingival dental plaque

Antimicrobial activities and biofilm-formation preventive properties of Mentha piperita and Cuminum cyminum essential oils and chlorhexidine were assessed against Streptococcus mutans and Streptococcus pyogenes. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis led to the identification of 26 and 32 compounds in the essential oils of M. piperita and C. cyminum, respectively. Minimal bactericidal concentrations (MBC) of the oils and chlorhexidine and microbial decimal reduction time (D value) were determined. Antibacterial and in vivo biofilm preventive efficacies of all the concentrations of M. piperita oil were significantly (p<0.001) higher. The biofilm inhibitory properties in planktonic cultures were in M. piperita > chlorhexidine > C. cyminum order. In vivo experiments conducted on male and female volunteers who brushed with essential oil blended toothpastes indicated that lower concentrations of the oils, in particular the M. piperita oil, were significantly higher (p<0.001) and effective during the course of the study as compared to chlorhexidine. In conclusion, there may be a potential role for essential oils in the development of novel anticaries treatments.     

α-Pinene- and β-myrcene-rich volatile fruit oil of Cupressus arizonica Greene from northwest Iran

Cupressus arizonica Greene is an aromatic evergreen coniferous plant with great importance in urban horticulture and in the pharmaceutical and fragrance industries. The hydrodistilled volatile fruit oil of cultivated C. arizonica from northwest Iran was analysed by GC/MS. Forty-three components were identified, accounting for 96.4% of the total oil. Monoterpenoids (91.9%) dominated the identified components of the essential oil, followed by a lesser portion of sesquiterpenoids (4.2%). Monoterpene hydrocarbons (87.9%) were the principal subclass of components, with α-pinene (54.3%), β-myrcene (11.1%), δ-3-carene (6.5%) and limonene (6%) as main constituents. β-Pinene (4%), terpinolene (2.8%) and camphene (1.1%) were the other monoterpenoids present in notable amounts. α-Terpineol (1.4%) was the only representative of the oxygen-containing monoterpenoids. Sesquiterpenoids had a minor share in the volatile oil's composition. Hydrocarbonic compounds (91.1%) had a higher share compared to the oxygenated components (5%). Comparison of the essential oil profile of C. arizonica Greene plants cultivated in Iran showed remarkable quantitative but slight qualitative differences with previous reports from other parts of the world. In summary, the chemical and percentage composition of the studied oil from cultivated C. arizonica Greene from northwest Iran was characterised by a high occurrence of α-pinene and β-myrcene, and is thus competent for use in related industries and as a favourite ornamental aromatic tree.     

Characterization of aroma active compounds in fruit juice and peel oil of Jinchen sweet orange fruit (Citrus sinensis (L.) Osbeck) by GC-MS and GC-O

Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel oil, respectively. GC-O was performed to study the aromatic profile of Jinchen fruit juice and peel oil. A total of 41 components appeared to contribute to the aroma of fruit juice and peel oil. Twelve components were the odorants perceived in both samples. The aromatic compositions of fruit juice were more complex than that of peel oil. Ethyl butanoate, beta-myrcene, octanal, linalool, alpha-pinene, and decanal were found to be responsible for the aromatic notes in fruit juice and peel oil. Nineteen components have been perceived only in the juice and ten compounds were described as aromatic components of only the peel oil by the panelists. These differences lead to the different overall aroma between fruit juice and peel oil.     

Improved solvent-free microwave extraction of essential oil from dried Cuminum cyminum L. and Zanthoxylum bungeanum Maxim

Solvent-free microwave extraction (SFME) is a recently developed green technique which is performed in atmospheric conditions without adding any solvent or water. SFME has already been applied to extraction of essential oil from fresh plant materials or dried materials prior moistened. The essential oil is evaporated by the in situ water in the plant materials. In this paper, it was observed that an improved SFME, in which a kind of microwave absorption solid medium, such as carbonyl iron powders (CIP), was added and mixed with the sample, can be applied to extraction of essential oil from the dried plant materials without any pretreatment. Because the microwave absorption capacity of CIP is much better than that of water, the extraction time while using the improved SFME is no more than 30 min using a microwave power of 85 W. Compared to the conventional SFME, the advantages of improved SFME were to speed up the extraction rate and need no pretreatment. Improved SFME has been compared with conventional SFME, microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD) for the extraction of essential oil from dried Cuminum cyminum L. and Zanthoxylum bungeanum Maxim. By using GC-MS system the compositions of essential oil extracted by applying four kinds of extraction methods were identified. There was no obvious difference in the quality of essential oils obtained by the four kinds of extraction methods.     

Composition and antimicrobial activity of the leaf and twig oils of Litsea mushaensis and L. linii from Taiwan

The hydrodistilled essential oils of the leaves and twigs of Litsea mushaensis and L. linii were analyzed. Sixty-nine and ninety compounds were identified in the leaf and twig oils, respectively, of L. mushaensis. The main components of the leaf oil were beta-eudesmol (24.2%), tau-cadinol (10.2%), alpha-humulene (10.1%), alpha-pinene (9.7%), and trans-beta-ocimene (6.5%), whereas the main components of the twig oil were trans-beta-ocimene (19.5%), alpha-pinene (12.8%) and cis-beta-ocimene (7.7%). With L. linii, 72 and 78 compounds were respectively identified in the leaf and twig oils. The main components of the leaf oil were beta-selinene (15.7%), alpha-selinene (15.5%), beta-caryophyllene (12.2%), alpha-humulene (7.2%), and delta-cadinene (5.6%), and of the twig oil trans-beta-ocimene (20.8%), beta-selinene (11.4%), alpha-cadinol (6.0%), delta-cadinene (5.8%), tau-cadinol (5.4%) and beta-eudesmol (5.2%). L. mushaensis leaf oil was shown to have excellent antimicrobial and anti-wood-decay fungal activity, superior to the other oils.     

纤维素酶前处理没药挥发油成分的GC/MS分析

采用水蒸汽蒸馏法分别从未处理和纤维素酶前处理的没药中提取挥发油,利用气相色谱-质谱(GC/MS)联用技术对其挥发油成分进行分析。从中分别鉴定出38种和34种化学成分,用峰面积归一法通过数据处理系统得出各化学成分在挥发油中的质量分数,占挥发油总成分的67.95%和70.05%。     

Analysis of the essential oil from aerial parts of Eupatorium cannabinum subsp. corsicum (L.) by gas chromatography with electron impact and chemical ionization mass spectrometry

Eupatorium cannabinum subsp. corsicum (L.), an aromatic plant, is an endemic subspecies from Corsica. The essential oil from aerial parts of E. cannabinum subsp. corsicum was studied by GC, GC/MS and 13C NMR. One hundred and forty-seven components were identified representing 93.6% of the total amount. The main constituents are germacrene D (28.5%), alpha-phellandrene (19.0%) and para-cymene (5.2%). A particularity of this essential oil is the presence of monoterpene esters derived from nerol, lavandulol, borneol, thymol and 8,9-dehydrothymol. These compounds have been investigated using GC/MS in different ionization modes like electron impact (EI), positive chemical ionization (PCI) and negative chemical ionization (NCI).