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采用水蒸气蒸馏法提取茵陈中挥发性成分挥发油,用气相色谱–质谱联用技术(GC–MS)对茵陈挥发油成分进行分析鉴定,并采用峰面积归一化法测定其相对含量。共检出52种挥发性成分,鉴定了其中31种主要挥发性成分,含量较高的组分为石竹素(15.27%)、(–)-斯巴醇(6.64%)、石竹烯(4.89%)等。GC–MS法适用于茵陈挥发性成分的定性分析,具有灵敏度高、分析速度快的特点。 相似文献
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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 总被引:5,自引:0,他引:5
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。 相似文献
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张裕XO级白兰地挥发性成分的提取分离与鉴定 总被引:4,自引:0,他引:4
建立了一套对白兰地挥发性物质进行预处理的方法,并采用气相色谱-质谱法(GC-MS)较全面地鉴定了白兰地的挥发性成分。实验先采用液-液萃取方法提取张裕XO级白兰地的挥发性成分,然后将酸性成分与碱性和中性成分分离,再采用柱色谱分离手段将其分离为若干个级分并浓缩,采用气相色谱-质谱、标准品比对、保留指数(RI)值比较等方法对分离得到的各级分中的成分进行了鉴定,在白兰地中共鉴定出302种挥发性成分,包括醇30种、醛酮类35种、酸类20种、酯类104种、苯同系物及其衍生物24种、酚类14种、缩醛14种、呋喃类16种、萜烯类22种和其他物质23种。结果表明,采用这套预处理方法能将白兰地的挥发性成分较有效地分组和浓缩。 相似文献
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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。 相似文献
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模式识别法分析5种植物油脂 总被引:2,自引:0,他引:2
通过模式识别方法区分花生油、大豆油、米糠油、棕榈油和菜籽油。采用气相色谱法分析5种植物油脂的脂肪酸,用面积归一化法计算每个植物油脂样品的各脂肪酸相对含量。以每个植物油脂中9个脂肪酸的相对含量为变量,采用SPSS13.0软件的模式识别技术对119个植物油脂样品进行区分。由主成分分析图可知,花生油、大豆油、米糠油、棕榈油和菜籽油被清晰地分为5组。判别分析建立的判别方程能较好地实现样品的判别,自身验证和交互验证的准确率均为100%。另取每种植物油脂各5个样品(共25个)进行验证,识别准确率为100%。对调和有棕榈油的花生油进行主成分分析,在主成分分析图上,调和油的分布点在花生油分布区域与棕榈油分布区域之间。 相似文献
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Microscopic observation and characterization of the oil bridge between dehulled-roasted sesame seeds
Takenaka N Iwamoto S Yabe T Yamauchi R Ogata K Kato K 《Colloids and surfaces. B, Biointerfaces》2007,55(2):131-137
The formation of an oil bridge between adhesive seeds was observed microscopically. The geometry of the oil bridge was affected by the shape of the adhesive seeds. The capillary force of the oil bridge was estimated from the image captured by the microscope. The average capillary force was 127 μN, which was five times higher than the average gravity of the seeds. It was observed that several oil bridges formed between two seeds. These results indicated an adequate ability of the seeds to adhere. The capillary force of the oil bridge increased with surface oil content. The probability of formation of an oil bridge increased with surface oil content when the surface oil content was above 0.63%. The probability of formation of an oil bridge markedly increased when sucrose was added to the seeds. 相似文献
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研究取样量对润滑油中微量水分测定结果的影响。基于卡尔·费休滴定法,在选定的测量条件下,用发生电极为有隔膜的自动库仑水分仪对基础油、有机热载体油、压缩机油、膨胀机油等新油和发动机油、汽轮机油、涡轮机油、压缩机油、齿轮油、液压油、导热油、船用油、电器绝缘油、风动工具油、金属加工油等在用油在0.1~2.0 g内各取9组不同质量的样品进行测定,得到了润滑油中微量水分准确测定所需的取样量。实验结果表明,新油取样量大于1.0 g,在用油取样量在1.0~1.5 g范围内,可以准确测定润滑油中微量水分含量。测定结果的相对标准偏差为0.83%~3.51%(n=10),样品加标回收率为95.0%~103.0%。在选择的取样量下,该方法具有良好的精密度、准确度,可连续测定多个样品,满足测定需求。 相似文献
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Production and Characterization of Biodiesel from Tung Oil 总被引:1,自引:0,他引:1
Park JY Kim DK Wang ZM Lu P Park SC Lee JS 《Applied biochemistry and biotechnology》2008,148(1-3):109-117
The feasibility of biodiesel production from tung oil was investigated. The esterification reaction of the free fatty acids
of tung oil was performed using Amberlyst-15. Optimal molar ratio of methanol to oil was determined to be 7.5:1, and Amberlyst-15
was 20.8wt% of oil by response surface methodology. Under these reaction conditions, the acid value of tung oil was reduced
to 0.72mg KOH/g. In the range of the molar equivalents of methanol to oil under 5, the esterification was strongly affected
by the amount of methanol but not the catalyst. When the molar ratio of methanol to oil was 4.1:1 and Amberlyst-15 was 29.8wt%
of the oil, the acid value decreased to 0.85mg KOH/g. After the transesterification reaction of pretreated tung oil, the purity
of tung biodiesel was 90.2wt%. The high viscosity of crude tung oil decreased to 9.8mm2/s at 40 °C. Because of the presence of eleostearic acid, which is a main component of tung oil, the oxidation stability as
determined by the Rancimat method was very low, 0.5h, but the cold filter plugging point, −11 °C, was good. The distillation
process did not improve the fatty acid methyl ester content and the viscosity. 相似文献
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利用衰减全反射傅里叶红外光谱法对掺假橄榄油进行了快速鉴别研究。对掺入转基因大豆油、非转基因大豆油、花生油、玉米油、葵花籽油、调和油等的橄榄油采用160℃高温加热8h处理,通过观察样品加热前、后二阶导数光谱在988cm-1处特征吸收峰的吸光度变化,准确鉴别橄榄油是否掺假。该方法操作简便、前处理无需有机试剂,可作为市场筛查掺假橄榄油的快速鉴别方法。 相似文献
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Parcerisa J Casals I Boatella J Codony R Rafecas M 《Journal of chromatography. A》2000,881(1-2):149-158
We analysed the triacylglycerol, tocopherol and sterol composition of hazelnut oil, olive oil and their mixtures (90% olive oil with 10% hazelnut oil, 70% olive with 30% hazelnut oil and 50% olive oil with 50% hazelnut oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmitoylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglycerol. Non-saponfiable compounds (tocopherols and sterols) were derivatised as O-trimethylsilyl ethers. Alpha-tocopherol was the main vitamin E isomer in all samples; however, small amounts of beta-tocopherol and gamma-tocopherol were also found. Beta-sitosterol and delta5-avenasterol were the principal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive oil and oil mixtures, was not found in hazelnut oil. The discriminant analysis showed that hazelnut oil, olive oil and oil mixtures were clearly separated according to their triacylglycerol composition. 相似文献
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基于费谢尔判别法的原油、燃料油鉴别技术研究 总被引:2,自引:0,他引:2
对原油、燃料油的鉴别方法进行了研究.以来自不同国家和地区的30个原油样品以及不同产地、不同种类的24个燃料油样品中的正构烷烃(n-C7~30)、植烷(Ph)、姥鲛烷(Pr)的含量构成训练集.借助SPSS 16.0进行费谢尔(Fisher)判别分析,建立Fisher判别函数.将判别变量值代入后,得到样本的空间位置,再计算样本至各组重心的距离,据此判断分类情况.结果表明,Fisher判别法可以很好地用于原油和燃料油的鉴别,具有快速、准确等特点. 相似文献
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柴油溶剂中脂肪酶催化高酸值废油脂酯化制备生物柴油 总被引:5,自引:1,他引:4
采用0#柴油作为反应溶剂,利用固定化脂肪酶催化高酸值废油脂与甲醇酯化反应制备生物柴油。来源于Candida antarctica的固定化脂肪酶Novozym435在0#柴油溶剂中具有极高的催化活性。以酸价高达157×10-3的废油脂为原料,废油脂质量比10%的Novozym435,甲醇与废油脂初始摩尔比2∶1,0#柴油与废油脂质量比5∶1,摇床摇速170r/min,50℃下反应2h甲酯化率可达95.10%。0#柴油作为反应溶剂有效地溶解了高酸值废油脂和甲醇,降低了反应体系的黏度和消除了甲醇对Novozym435的负面影响,提高了Novozym435的稳定性。同时,0#柴油溶剂对未脱胶废油脂中残留的对脂肪酶有害的磷脂等胶类物质具有一定的稀释作用。该工艺省却了溶剂蒸馏的繁琐工序,直接得到脂肪酸甲酯和石化柴油的混合燃料。 相似文献