顶空固相微萃取-气相色谱-质谱法测定茶叶中香叶醇

建立了一种应用顶空固相微萃取(HS-SPME)气相色谱质谱(GC-MS)联用分析测定茶叶中香叶醇(Geraniol)的方法。通过考察萃取头型号、茶水比、萃取温度、萃取时间、解吸附温度和解吸附时间等影响因素,确定最佳HS-SPME条件为:DVB/CAR/PDMS型号萃取头、茶水比1:6、萃取温度60℃、萃取时间60 min;气相色谱最佳解吸附条件为:进样口温度240℃、解吸附时间3 min。在优化条件下茶叶样品中的香叶醇得到较好的提取,GC-MS检测线性范围为0.08~16.50μg/g,检出限(S/N≥3)为9.42×10-3μg/g,空白基质加标回收率为89.8%~105.9%。在对24种茶样进行检测后,香叶醇含量范围为0.13~11.85μg/g,相对标准偏差为1.8%~9.7%。方法能满足茶叶样品中香叶醇分析测定的需要。     

顶空固相微萃取-气相色谱-质谱法分离鉴定金华火腿的挥发性风味物质

采用顶空固相微萃取法(HS-SPME)制备样品,利用气相色谱-质谱法（GC-MS）分离鉴定了金华火腿的挥发性风味物质。实验中筛选了固相微萃取纤维头,优化了固相微萃取的操作条件。用75 μm碳分子筛/聚二甲基硅氧烷（CAR-PDMS）纤维头,于60 ℃下对金华火腿样品顶空吸附40 min,于250　℃下解吸2 min,采用GC-MS对解吸物进行分离鉴定。金华火腿样品的分析结果表明,其挥发性风味物质中含量较高的是醛、酸和酮类化合物,还有一些含硫或杂环化合物。     

气相色谱-质谱法分析啤酒中酒花香气成分

利用顶空固相微萃取-气相色谱质谱技术(HS-SPME/GC-MS)建立了定量分析啤酒中19种源自酒花的微量香气成分的方法。研究了不同萃取头、萃取时间、萃取温度对萃取效果的影响,最终确定HS-SPME最佳萃取条件为采用PDMS萃取头对啤酒样品在50℃下萃取60 min。在最佳萃取条件下,采用啤酒为基体以减少基体干扰,建立标准曲线,随后在SIM模式下以萜品烯-4-醇为内标定量测定了啤酒中酒花香气物质的含量。19种物质的回收率在81.2%～116.8%之间,相对标准偏差(RSD)低于9.8%,在5个加标浓度下,R2大于0.99。相比于传统方法,本方法所需样品量少、灵敏度高、操作过程简便,能准确的检测出啤酒中酒花香气物质的含量。     

顶空固相微萃取-气相色谱-质谱法快速测定酱油中的挥发性风味成分

建立了一种快速简便地测定酱油中挥发性风味成分的顶空固相微萃取（HS-SPME）-气相色谱-质谱法(GC-MS)。以2-辛醇为内标,考察了萃取头、萃取时间、离子强度、萃取温度对酱油样品中挥发性风味物质萃取的影响。该方法对酱油中常见挥发性风味成分的测定有良好的重复性和回收率,对常见挥发性物质的定量比较准确。优化的HS-SPME条件为：涂层厚度为85 μm聚丙烯酸酯(PA)萃取纤维头,于45 ℃、NaCl质量浓度为250 g/L下对酱油样品顶空吸附40 min,于250 ℃下解吸2 min后进行GC-MS分离鉴定。酱油样品的分析结果表明,其挥发性风味物质中含量较高的是醇、酸、酯和酚类,此外还有一些羰基化合物和杂环化合物。     

顶空固相微萃取-气相色谱-质谱联用分析费约果叶片挥发性香气成分条件优化

为了建立适合费约果叶片香气成分检测的顶空固相微萃取-气相色谱-质谱（HS-SPME-GC-MS）分析方法,考察HS-SPME中不同萃取条件对香气萃取效果的影响,采用L₉（3⁴）正交试验,以出峰个数和总峰面积为考察指标确定最佳萃取条件。结果表明,萃取温度对出峰个数和总峰面积的影响较大,而加样量的影响较小。实验得出的较优萃取条件为：加样量0.6 g,萃取温度50 ℃,萃取时间50 min,解吸时间6 min。在此萃取条件下能够得到88种物质,这些物质能更真实地反映费约果叶片香气成分的化学构成,为费约果叶片的开发利用提供有价值的数据。     

固相微萃取-气相色谱-质谱法测定牡丹花挥发油中各成分

采用固相微萃取-气相色谱-质谱法分离和测定牡丹花中挥发油成分,用归一化法测定其相对含量。为使固相微萃取达到更高的效率,选用50/30μm PDMS/DVB/CAR的固相萃取头,萃取温度及时间为45℃和40min。共检出38种化合物,总质量分数为2 481.34ng·g-1。其中乙酸己酯、香茅醇、香叶醇和丙酸香叶酯等物质为构成牡丹花的特征香气的重要成分。     

顶空-固相微萃取法与水蒸气蒸馏法提取沙棘挥发油组分的比较研究

优化了顶空-固相微萃取法(HS-SPME)提取沙棘挥发性成分的条件,并采用气相色谱-质谱联用技术(GC-MS)分别对HS-SPME法和水蒸气蒸馏法(SD)的提取物进行分析。结果显示,在萃取温度为70℃,萃取时间为50 min,解吸时间为7 min,平衡时间为20 min条件下,HS-SPME法鉴定出76种组分,占挥发性物质总量的90.19%,主要成分为酯类、醛类和酮类;而SD法提取物共鉴定出56种组分,占挥发性物质总量的91.98%,主要成分为酯类。2种方法共有组分为20种。两种方法提取的沙棘挥发油组分的种类及含量差异较大,HS-SPME法更适合沙棘挥发性组分的快速检测。     

顶空固相微萃取-气相色谱-质谱法用于白术中挥发性成分的分析

采用顶空固相微萃取-气相色谱-质谱法(HS-SPME-GC-MS)分离鉴定了白术中的挥发性成分,并与采用传统的水蒸气蒸馏法(SD)提取的挥发性成分进行了比较。实验中筛选了固相微萃取纤维头,优化了SPME的操作条件。样品在70 ℃下平衡30 min后,用65 μm聚二甲基硅氧烷-二乙烯基苯(PDMS-DVB)纤维头对白术样品顶空吸附30 min,于250 ℃下解吸4 min, 然后采用GC-MS对解吸物进行分离鉴定;采用HS-SPME-GC-MS鉴定出41种组分,占总峰面积的90.81%;采用SD-GC-MS鉴定出31个组分,占总峰面积的88.19%,且采用SD所提取的组分基本上都被固相微萃取所提取。结果表明, HS-SPME可取代耗时的SD用于白术中挥发性物质的提取。     

固相微萃取-气相色谱-质谱法分析树苔浸膏的香气成分

采用固相微萃取-气相色谱-质谱法分离和鉴定树苔浸膏的香气成分,用归一化测定其相对含量。为使固相微萃取达到更高的效率,选用100μm PDMS的固相萃取头,萃取温度及时间为65℃和30min。共鉴定出62种化合物,其中33种为酯类化合物,占总香气成分峰面积的58%,为构成树苔浸膏典型苔清香香气特征的重要成分。     

11种啤酒关键老化指示物的检测方法

利用顶空固相微萃取-气相色谱质谱技术(HS-SPME/GC-MS),建立了一种同时检测啤酒中基于不同老化反应的11种老化指示性物质的定量分析方法。通过优化萃取头种类、萃取时间、萃取温度等条件,最终确定HS-SPME最佳萃取条件为使用2cm的DVB/CAR/PDMS(涂层厚50/30μm)萃取头、50℃下萃取40 min。质谱采集SIM模式,内标物质使用对氟苯甲醛。该方法的线性良好(R2>0.99),准确性高(11种物质的加标回收率在82.6%～102%之间),稳定性强(相对标准偏差均低于16%),能同时准确检测出麦汁、发酵液和啤酒中反映不同老化机理的不同老化指示物质的含量,适用于啤酒老化研究和调控的日常检测。     

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.     

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。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

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.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

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.     

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^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。