肉桂挥发油的超临界CO2萃取法与水蒸气蒸馏法提取的比较分析

采用超临界CO2萃取法与水蒸气蒸馏法从肉桂中提取挥发油,用GC-MS法测定其化学成分和相对含量,对两种提取方法所得的挥发油进行比较,水蒸气蒸馏提取肉桂挥发油的产率为1％(ω),主要成分为肉桂醛、α-芹子烯、α-（王古）Ba烯、δ-杜松烯;超临界CO2萃取法提取的产率为1．5％(W),主要成分为肉桂醛、α-玷圯烯、α-依兰油烯、δ-杜松烯等。     

气相色谱-质谱联用法测定黄兰中挥发油化学成分

采用水蒸气蒸馏法、超临界萃取法、微波辅助提取法与超声波辅助萃取法等4种提取方法提取黄兰挥发油,运用毛细管气相色谱-质谱联用法结合计算机检索对其挥发油化学成分作了鉴定和测定.结果显示从水蒸气蒸馏法、超临界萃取法、微波辅助提取法与超声波辅助萃取法所得挥发油中分别鉴定出了36,35,25和26种化合物.用面积归一法测定了4种挥发油中各种化学成分的相对百分含量,各占总峰面积的92.62%,91.46%,93.18%和95.53%.虽然不同提取方法所得的4种挥发油化学成分有所不同,但其中有20种化合物包括β-荜澄茄烯、大根香叶烯D、丁香烯氧化物、丁香烯等为4种挥发油提取物所共有.     

薤白挥发油成分的超临界CO2萃取及GC-MS分析

采取超临界CO2萃取和水蒸气蒸馏两种方法提取薤白中的挥发油,比较了两种提取方法得到的挥发油的理化性质,并利用GC-MS对它们进行了定性、定量分析。两种方法的主要提取物均为含硫化合物,但超临界CO2萃取法得到的含硫化合物的数量和质量都高于水蒸气蒸馏法得到的提取物。采用水蒸气蒸馏法提取8 h得到的萃取率为1.72%。通过设计的超临界CO2萃取的正交实验,得到了最佳萃取工艺条件为:压力25 MPa,温度40℃,CO2流量为25L/h。最佳萃取时间为120 min,萃取率为4.41%,是水蒸气蒸馏法萃取率的2.8倍。实验结果表明,超临界CO2萃取法简单易行,可以较快速、有效地提取薤白中的挥发油。     

超临界CO2流体萃取法与水蒸气蒸馏法提取荆芥穗挥发油化学成分的研究

采用超临界CO2萃取法(SFE)与水蒸气蒸馏法(SD)从荆芥穗中提取挥发油。采用SE-54毛细管柱进行分析,用气相色谱-质谱法对挥发油中各种化学成分进行鉴定,用归一化法测定各组分的含量。色谱条件:SE-54毛细管柱 (30 m×0.25 mm i.d.,0.25 μm),柱温50 ℃(3 min)5 ℃/min180 ℃(2 min)10 ℃/min260 ℃(50 min);分流进样,分流比1∶50;进样口温度280 ℃。在采用超临界CO2萃取法提取的挥发油中共鉴定出54种成分,其主要成分为长叶薄荷酮、薄荷酮、亚油酸氯化物等;在水蒸气蒸馏法提取的挥发油中共鉴定出39种成分,其主要成分为长叶薄荷酮、薄荷酮、柠檬烯等。超临界法较水蒸气法更加稳定可靠,重现性好,适用于中药挥发油的化学成分分析。     

超临界CO2萃取与水蒸气蒸馏法研究泽兰中挥发性有机物

以超临界CO2萃取法(SFE)提取中药泽兰中的挥发性有机物,经气相色谱-质谱联用(GC-MS)分析,人工解析质谱图及计算机谱库检索相结合进行化学成分结构鉴定,用面积归一化法计算各组分的相对含量。SFE法提取的产率为0.78%,共鉴定75种挥发性化合物,主要成分为植醇、石竹烯氧化物、十六酸、亚油酸、葎草烯等,比文献报道的该挥发油成分多且含量差异较大,其中松香芹醇、蒲勒烯、马鞭烯酮、香芹酮、十六酸、亚油酸、葎草烯、十六酸乙酯、亚麻酸等多种成分未见报道。与水蒸气蒸馏法(SD)提取的泽兰挥发油进行比较,后者提取的产率为0.12%,从中鉴定出50种化合物,主要成分为石竹烯氧化物、柠檬烯、α-蒎烯、葎草烯、月桂烯等。SFE与SD得到的成分仅有31种相同,其它各不相同。     

超临界CO_2萃取-分子蒸馏对白术挥发油的提取分离和GC-MS分析

用超临界CO2萃取技术提取白术挥发油，然后用分子蒸馏对所得的萃取物进行精分离，得到蒸出物；超临界萃取物收率为2．42％(w)，分子蒸馏蒸出物收率26．3％(w)；对超临界萃取物和分子蒸馏蒸出物分别进行GC—MS分析，结果超临界萃取物检测出33个化合物，分子蒸馏蒸出物检测出27个化合物，主要成分均为2，7-二甲氧基-3，6-二甲基萘、γ-芹子烯、大根香叶烯等，但相对含量有区别。     

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。     

芹菜籽香气成分研究

采用固相微萃取法萃取黑龙江产芹菜籽香气成分,然后用GC—MS进行成分分析,并与水蒸气蒸馏法获得的精油成分进行比较．用CAR on PDMS萃取柱进行顶空固相微萃取时,共检测出26种成分,鉴定出占总成份89．650％的20种成分,主要成分为柠檬烯（35．980％）,β-月桂烯（20．500％）,β-蛇床烯（16．160％）,正戊基苯（5．295％）,β-蒎烯（3．412％）,α-蛇床烯（3．293％）．水蒸汽蒸馏法提取芹菜籽,以1．18％产率获得精油,共检测出23个成分,鉴定出占总精油91．375％的18种成分,主要成分为柠檬烯（31．149％）,β-蛇床烯（22．281％）,对甲苯基异戊酸酯（14．944％）,α-2-丙烯基苯甲醇（9．872％）,β-月桂烯（4．324％）和α-蛇床烯（4．322％）．     

超临界萃取中药白芷的化学成分的气相色谱质谱分析

采用超临界流体萃取法对传统中药白芷的化学成分进行了分离提取研究，利用气相-质谱联机技术，对其中的55种化学成分进行了鉴定，并测定了相对含量。与传统的水蒸气蒸馏法提取的白芷挥发油进行了比较，分析。实验结果表明，超临界CO2萃取法所得的产物，能保留药材白芷的所有有效成分，可以入药。     

蓝布正挥发油化学成分的GC-MS分析

研究贵州产蓝布正（Herba Gei）挥发油的化学成分，采用水蒸气蒸馏法提取蓝布正挥发性成分，用气相色谱－质谱进行分离测定，结合计算机检索技术对分离的化合物进行鉴定，应用色谱峰面积归一化法测定各成分的相对含量；水蒸气蒸馏提取物得率是0．10％，共分离出103种成分，鉴定出40个化学成分，其主要成分为脂肪酸及其甲酯类化合物、萜烯类及其含氧衍生物等，主要有棕榈酸（13．2％）、11，14，17－二十碳三烯酸甲酯（10．4％）、亚油酸（8．6％）、石竹烯氧化物（3．9％）、丁子香酚（3．4％）和反式－植醇（3．2％）等。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.