石油醚

The research aimed to study the chemical constituents from Swertia chirata extracted with petrolelum ether.

［目的］研究印度獐牙菜石油醚部位化学成分。

S. chirata ethanol-extracts was extracted with petrolelum ether, ethyl acetate and butanol, respectively.

方法］分别用石油醚、乙酸乙酯和正丁醇萃取印度獐芽菜乙醇浸膏，所得产物用硅胶柱、Sephadex LH-20柱洗脱后进行结构鉴定。

Chirata, and they were identified as β-sitosterol and swerchirin by spectral method. These two compounds were got firstly from the petrolelum ether fraction of S. chirata.

结论］2种化合物β-谷甾醇与1，8-二羟基-3，5二甲氧基山酮均为首次从印度獐芽菜乙醇提取物的石油醚部位分离得到。

Objective To investigate the chemical constituents of the petroleum and the chloroform extracts of Ledum palustre L.

目的对细叶杜香石油醚和三氯甲烷部位的化学成分进行研究。

Chloropicrin in vegetables and fruits was determined by gas chromatography with ECD after extracted with petroleum ether under ultrasonic.

采用石油醚对蔬菜、水果样品进行超声波提取，以气相色谱电子捕获检测器测定氯化苦残留。

Also the molecular structure and functional effects of this active component were studied in detail. 1 Extraction, separation, purification and structural identification of the functional component in Chufa After initial handling of waste slurry to solid powder, ethanol was used to lixiviate it followed by the extraction with petroleum ether,ethyl acetate,n-butyl alcohol one by one, the polarity of three organic reagents being changed from low to high.

荸荠功能因子的提取、分离、纯化及结构鉴定以马蹄粉厂产粉废浆为原料，经过实验室初处理成固态原料粉后，用乙醇浸提，再将浸提物以水悬浮，依次通过极性从小到大的石油醚、乙酸乙酯、正丁醇三种有机溶剂两相萃取分部，并以金黄葡萄球菌、枯草芽孢杆菌和致病大肠杆菌为指示菌，检测上述各部分提取物的功能效果。

Cottonseed oil and cottonseed meal with good quality could be obtained from cottonseed kernel by a two - phase extraction system which was composed of petroleum ether and methanol.

采用石油醚和甲醇的双液相溶剂浸取棉仁可以得到高质量的棉籽油和棉籽粕，棉仁中的棉酚大部分被甲醇溶解。

The appropriate temperature of diazotization was-10～-5℃,and the diazotizating fluoborate was decomposed in petroleum ether to get 2-chloro-3-fluoropyridine with 64% yield.

以2-氯-3-氨基吡啶为原料，在40%的氟硼酸溶液中，采用饱和的亚硝酸钠为重氮化剂，在-10~-5℃下进行重氮化反应制得重氮盐，在石油醚中热分解得到2-氯-3-氟吡啶，收率为64%。

Electropolar solvent such as THF may destroy the polyetherimide layer,while non-electropolar solvent such as petroleum ether cannot solve vinyl acetic acid cobalt.

极性溶剂如四氢呋喃会溶解PEI层，而非极性溶剂如石油醚又不能溶解丁烯酸钴。

The optimun conditions were pressure 300 Mpa,temperature 45 celsius degree,extraction time 3h and the entrainer was petroleum ether.

确定工艺条件为：压力30MPa，萃取温度45℃，萃取时间3 h，携带剂为石油醚。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。