毛蕊杜鹃挥发油化学成分研究

毛蕊杜鹃(Rhododendron tubulosum Ching ex wang wei-yei)系杜鹃花科杜鹃花属植物,分布于四川、西藏、甘肃和青海,其中青海分布最广,藏民常作为单方草药用于治疗肺炎和老年慢性气管炎,具有镇咳、祛痰作用,本文用自制的同时水汽蒸馏-溶剂萃取装置,从采自青海玉树州的毛蕊杜鹃鲜叶和嫩枝提取挥发油,用毛细管气相色谱-质谱和Kovats指数双重定性法对     

新型聚丙烯酸酯类柴油降凝剂分子模型的建立及验证

在前期工作得出的正构烷烃含量与浊点、冷滤点、凝点的定量关系模型基础上，选择柴油降凝剂的基团对柴油降凝剂分子结构进行了设计，得出了设计模型。结果表明，将含氮基团引入柴油降凝剂可以显著提高柴油降凝剂的性能。根据设计模型合成了一系列聚丙烯酸单酯和混合酯柴油降凝剂，并通过对柴油降凝剂的性能测试结果和自行设计的计算程序对设计模型进行了验证，结果表明，从柴油正构烷烃含量对柴油降凝剂的配比进行设计是可行的。     

Dynamic Interfacial Tension Behavior of Water/Oil Systems Containing In situ-Formed Surfactants

Time-dependent interfacial tension (IFT) has been investigated for an interfacially reactive immiscible system composed of model-acidified oil and alkaline water. The acidified oil was composed of either lauric acid or linoleic acid dissolved in n-dodecane. Drop volume tensiometry was employed to measure the interfacial tension between the two phases. In the case of lauric acid, the IFT value was found to decrease sharply with increasing alkali concentration, even at low drop formation times. In the case of linoleic acid, the IFT decrease with the drop formation time was more gradual, especially at low alkali concentration. The rate of formation of the interfacial area was also found to be dependent on alkali concentration.     

Feasibility of using solid sampling graphite furnace atomic absorption spectrometry for speciation analysis of volatile and non-volatile compounds of nickel and vanadium in crude oil

A method for the direct determination of volatile and non-volatile nickel and vanadium compounds in crude oil without previous treatment using direct solid sampling graphite furnace atomic absorption spectrometry is proposed. The crude oil samples were weighed directly onto solid sampling platforms using a microbalance and introduced into a transversely heated solid sampling graphite tube. In previous work of our group losses of volatile nickel and vanadium compounds have been detected, whereas other nickel and vanadium compounds were thermally stable up to 1300 and 1600 °C, respectively. In order to avoid this problem different chemical modifiers (conventional and permanent) have been investigated. With 400 μg of iridium as permanent modifier, the signal started to drop already after two atomization cycles, possibly because of an interaction of nickel (which is a catalyst poison) with iridium. Twenty micrograms of palladium applied in each determination was found to be optimum for both elements. The palladium was deposited on the platform and submitted to a drying step at 150 °C for 75 s. After that the sample was added onto the platform and submitted to the furnace program. The influence of sample mass on the linearity of the response and on potential measurement errors was also investigated using four samples with different nickel content. For the sample with the lowest nickel concentration the relationship between mass and integrated absorbance was found to be non-linear when a high sample mass was introduced. It was suspected that the modifier had not covered the entire platform surface, which resulted in analyte losses. This problem could be avoided by using 40 μL of 0.5 g L⁻¹ Pd with 0.05% Triton X-100. Calibration curves were established with and without modifier, with aqueous standards, oil-in-water emulsions and the certified reference material NIST SRM 1634c (trace metals in residual fuel oil). The sensitivity for aqueous standards and emulsions was close to that for SRM 1634c, making possible the use of aqueous standards for calibration. The limits of detection and quantification obtained for nickel and vanadium under this condition were found to be 0.02 and 0.06 μg g⁻¹, respectively, for both elements, based on 10 mg of sample. Nickel and vanadium were determined in the samples with (total Ni and V) and without the use of Pd (thermally stable compounds), and the concentration of volatile compounds was calculated by difference. The results were compared with those obtained by high-resolution continuum source graphite furnace atomic absorption spectrometry by emulsion technique; no significant differences were found for total Ni and V at the 95% confidence level according to a Student's t-test.     

Essential Oil of Arischrada korolkowii from the Chatkal Mountains of Uzbekistan

The herbal parts of Arischrada korolkowii (Regel et Schmalh.) Pobed. (Lamiaceae) growing in Uzbekistan were hydrodistillated to yield 1.1% of essential oil. The essential oil was analyzed by GC/MS. Eighty eight compounds were characterized representing 98% of the essential oil with 1,8-cineole (29.3%), camphor (9.8%), -caryophyllene (8.5%), bornyl acetate (7.7%), caryophyllene oxide (7.2%), and borneol (5.6%) as the main constituents.     

白术挥发油中苍术酮氧化反应的动力学

白术挥发油;苍术酮;动力学方程;活化能;反应机理     

气相色谱-质谱联用技术测定水中油

本文综述了近年来用气相色谱法测定水中油的技术进展。引用文献13篇。     

Identification of a chemical indicator of the rupture of 1,4-β-glycosidic bonds of cellulose in an oil-impregnated insulating paper system

In this study, headspace gas chromatography/mass spectrometry has been used to assess the volatile by-products generated by the ageing of oil-impregnated paper insulation of power transformers. Sealed-glass ampoules were used to age under oxidative conditions 0.5-g specimens of insulating paper in 9 mL of inhibited mineral oil in a temperature range of 60–120 °C and moisture of 0.5, 1 and 2% (w/w). A linear relationship between one of the oil-soluble degradation by-products, i.e. methanol, and the number of ruptured 1,4-β-glycosidic bonds of cellulose, regardless of the type of paper (ordinary Kraft or thermally-upgraded (TU) Kraft paper), was established for the first time in this field. Ageing at 130 °C of model compounds of the Kraft paper constituents (α-cellulose, hemicellulose and lignin) and two cellulosic breakdown by-products (D-(+)-glucose and 1,6-anhydro-β-d-glucopyranose) confirmed that the α-cellulose degradation was mostly responsible for the presence of this molecule in the system. Furthermore, additional 130 °C-tests with six different papers and pressboard samples under a tight control of initial moisture indicated that at least one molecule of methanol is formed for each rupture of 1,4-β-glucosidic bond of the molecular chains. Stability tests showed that the ageing indicator is stable under the oxygen and temperature conditions of open-breathing transformers. The presence of methanol was detected in 94% of oil samples collected from over than 900 in-service pieces of equipment, confirming the potential for this application. Lastly, the tests have shown that oil-oxidation by-products and TU-nitrogenous agents modify the methanol partitioning coefficients in the paper/oil/air system, which makes their study essential over a range of field conditions encountered by power transformers. Results are presented and discussed in comparison with 2-furfuraldehyde, which is the current reference in the domain.     

从蓖麻油制取10-羟基癸酸的研究

本文报道了从蓖麻油制取10-羟基癸酸的研究,发现了从蓖麻油制取10-羟基癸酸的新的工艺路线和最佳的工艺条件,用氢氧化钠用量、2-辛醇量、反应时间和反应温度四因子三水平L_9(3~4)进行了正交试验,发现最佳工艺条件是:氢氧化钠(g)/蓖麻油(g):1.25:2-辛醇量(g)/蓖麻油(g):2:反应时间:6h;反应温度:180℃。在这一新的工艺路线和最佳工艺条件下,10-羟基癸酸产率可达75％。     

Decomposition of Transformer Oil Under Ultrasonic Irradiation During Degassing Process

In the degassing process of transformer oil with ultrasonic waves ,decompostition of the oil was observed.Light hydrocarbons,including methane,ethane,ethylene ,aceylene,propane etc,were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field ,The gases came from decomposition of hydrocarbon molecules under cavitation effect.