Isolation of essential oils from tobacco by gas co-distillation/solvent extraction

Summary The essential oils have been isolated from tobacco leaves using a simple gas co-distillation apparatus. The method involves co-distillation with water under the continuous stream of an inert gas with subsequent single solvent extraction of the distillate. The extract is analysed on GC and GC/MS in splitless injection mode without further concentration. The method was evaluated for reproducibility using n-octadecane as an internal standard. The distillation-extraction procedure was reporducible with an average deviation of ±3% for the major constituents. The present method was applied to the analyses of the essential oils of other agricultural products.Dedicated to Dr. L. S. Ettre on the occasion of his 60th birthday.     

精油化学的进展

本文粗略回顾了精油化学的新进展,对精油的研究方法、精油成分的合成及生源也有所论述。同时介绍了当前精油研究中常用的文献。     

Structure elucidation of triglycerides by chromatographic techniques. Part 1: Capillary GC of ozonized triglycerides

Structure determination of triglycerides according to their number of unsaturated fatty acids (N.U.F.A.) is more easily achieved after ozonolysis of their mixtures (fats and oils) than by capillary gas chromatographic analysis of the mixture as such. Analyses performed before and after ozonolysis of cocoa buttel, hazelnut oil, and a mixture of both fats illustrate the potential of this approach to the structure elucidation of triglycerides by chromatographic techniques.     

Analysis of Essential Oil from the Needles of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Growing in Algeria

The needle oil of the Algerian maritime pine (Pinus pinaster Ait.) growing in natural habitats in Sidi Feradj (Algiers region) was obtained by hydrodistillation in 0.3% yield and analyzed by GC and GC/MS. More than 46 compounds amounting to 65.2% of the total oil were identified. The main components were β-caryophyllene (26.6%), allo-aromadendrene (12.5%), and α-humulene (4.3%). __________ Published in Kimiya Prirodnikh Soedinenii, No. 5, pp. 445–447, September–October, 2005.     

Composition and major odorous compounds of the essential oil of Bifora radians,an aldehyde-producing weed

The composition of the essential oil of Bifora radians, an aldehyde-producing weed, has been investigated by capillary gas chromatography, coupled gas chromatography – mass spectrometry, on-line catalytic hydrogenation and coupled gas chromatography – infrared spectrometry. The nineteen compounds identified included eighteen aldehydes: seven alkanals (C6, C9, C10, C11, C12, C13, and C14), ten alkenals, including five (E)-2-alkenals (C12, C13, C14, C15, and C16), and one (E,E)-2,4-alkadienal (C13). Typical Bifora odors were attributed to three major (E)-2-alkenals, C12, C13, and C14.     

Determination of Pesticide Ethion by Linear Sweep Stripping Voltammetry

IntroductionOrganophosphorus pesticides( OPPs) are widelyused in agriculture as insecticides, but they are foundto contaminate agricultural products such as fruits andvegetables to variable extents. Because of their toxicproperties[1,2]and the potential r…     

液相色谱电化学安培检测乳粉中的脂溶性维生素A, E和D3

利用维生素A、D3、E均有电化学活性的特点,采用电化学安培检测,建立了HPLC检测奶粉中的脂溶性维生素A、D3、E的新方法.流动相为甲醇∶水=95∶5(V/V),含0.05 mol/L高氯酸钠.检测器采用玻碳电极,直流安培模式(DC),氧化电位 1.3 V.方法检测限为:VA、VD3、-αVE、-γVE、-δVE分别为0.08、2.3、0.16、0.19、0.28ng.回收率分别为:90.2%~98.2%、91.2%~103%、92.7%~99.5%、92.6%~97.4%、90.7%~98.0%.同紫外检测比较,方法具有灵敏度高、抗干扰强的特点.     

毛细管气相色谱法测定油中植物甾醇和胆固醇

采用2.0mol/L的氢氧化钾乙醇溶液在85℃水浴上皂化45min，石油醚萃取，毛细管气相色谱法分离植物甾醇和胆固醇的分析方法，讨论并确定了样品皂化的最佳条件。用该法测定了芝麻油中甾醇的含量，相对标准偏差为0.86%-4.13%；回收率为89.59%-103.09%。结果表明：采用该方法具有操作快速、简便、准确等优点。