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1.
生姜挥发油的提取及其化学成分的气相色谱-质谱分析   总被引:9,自引:0,他引:9  
本文对生姜挥发油的提取先采用水蒸气蒸馏法,然后对馏出液用已醚萃取,得到提取物Ⅰ,经GC/MS检测鉴定出40种化合物。对乙醚萃取后的馏出液选用乙酸乙酯进一步提取,用GC/MS检测还鉴定出28种化合物,提取出的挥发油重量占总油量39%。  相似文献   

2.
生姜挥发油的提取及其化学成分的气相色谱—质谱分析   总被引:1,自引:0,他引:1  
张宏  张宏桂 《分析化学》1996,24(3):348-352
本文对生姜挥发油的提取先采用水蒸气蒸馏法,然后对馏出液用乙醚萃取,得到提取物I,经GC/MS检测出40种化合物,对乙醚萃取后的馏出液选用乙酸乙醋进一步提取,用GC/MS检测还鉴定出28种化合物,提取出的挥发油重量占总油量39%.  相似文献   

3.
用色质联用(GC/MS)法测定酱香型酒空杯香的化学成分,鉴定出13种化合物,并测定了它们的相对含量,其中以十六酸乙酯、油酸乙酯、亚油酸乙酯为主。  相似文献   

4.
肖定军  马伟杰  邓松之 《分析化学》2004,32(12):1621-1623
从中国南海海绵Spheciospongia Vagabunda乙酸乙酯萃取部分中分离出一组混合物,应用^13HNMR,^13CNMR,H-HCOSY和GC/MS等光谱分析技术对它们的结构进行了分析,主要为一些长链甲基酮化合物。共鉴定出二十四碳烯-2-酮异构体、二十四碳二烯-2-酮和二十四碳烯-2-酮等14种化合物,其中4种化合物的双键位置有待于进一步确定。  相似文献   

5.
对7种含“单”或“双”吡唑啉化合物在溶液在固体器「ITO/TPD/TPB1-2%EP/TPBI/Mg-Ag」中作为掺杂发光材料的电致发光特性地研究,结果表明,由吡唑啉化合物所构成的器件具有优良的电致发光特。  相似文献   

6.
顶空固相微萃取-气相色谱-质谱测定水中异味化合物   总被引:20,自引:1,他引:20  
李林  宋立荣  甘南琴  陈伟 《分析化学》2005,33(8):1058-1062
采用顶空固相微萃取-气相色盐/质谱联用测定了水中常见的3种异味化合物,即2-甲基异茨醇、土腥素和β-柠檬醛。研究并讨论了纤维头的类型、盐的种类和浓度、温度、萃取时间、搅拌和解吸时间等因素对异味化合物萃取量的影响。结果表明:在水样中加入30%(W/V)的NaCl溶液,采用65μm PDMS/DVB纤维头,在搅拌的条件下,于60℃顶空萃取40min为异味化合物固相微萃取的最佳条件。在优化的条件下,使异味化合物吸附于纤维涂层后,将其在250℃高温下解吸,再用GC—MS分析。土腥素、β-柠檬醛、2-甲基异茨醇的检出限依次为1.0、1.3和1.7ng/L;其相对标准偏差分别为4.9%、8.4%和6.2%:3种异味化合物在5~1000ng/L的范围内线性关系良好,相关系数均大于0.997。因此,用该方法分析水中痕量(ng/L级)的异味化合物,结果满意。  相似文献   

7.
三环己基和三苯基锡化合物的质谱重排反应及配位效应   总被引:1,自引:0,他引:1  
宋凤瑞  包明 《分析化学》1997,25(6):675-678
研究了18种新合成的有机锡化合物的电子轰击质谱,利用B/E联动扫描及碰撞诱导解离技术,研究了该类化合物的几种特殊的重排反应机理,同时探讨了与锡配位的基团对其断裂规律的影响。  相似文献   

8.
高效液相色谱法测定小鼠脑组织单胺递质及其相关化合物   总被引:12,自引:0,他引:12  
采用苯基柱等度洗脱分离,自然荧光检测法,直接测定小鼠脑组织匀浆中单胺递质及其相关化合物。优化出了最佳色谱条件,流动相为20mmol/L柠檬酸三钠(pH4.50)-甲醇(95:5,V/V);柱温为35℃。该方法能同时检测8种化合物。最低检测限为1.0-2.5μg/L,回收率均在935以上;线性范围为1.0μg/L-1.0mg/L。  相似文献   

9.
通过克莱森-施密特(Claisen-Schmidt)反应合成了一种新型双查尔酮衍生物1,4-二[3-(3,4,5-三甲氧基苯基)-2-丙烯酰基]苯(BTAB)。该化合物的结构通过核磁共振波谱仪(NMR)和质谱等技术手段得到确认。采用热综合分析方法测定了DSC/TG曲线,发现该化合物的熔点为230.6℃,热稳定性良好。测定了该化合物的紫外光谱和荧光光谱,λmax/UV=357.5 nm,λmax/EM=541 nm,表现出较大的紫外吸收波长和荧光发射波长。采用密度泛函理论方法计算获得了BTAB分子的最高占据轨道与最低空轨道能量和极化率,从前线分子轨道组成图发现存在分子内电荷转移现象。用单光束Z-扫描技术获得了BTAB的非线性光学特性,其三阶非线性吸收系数β=3.15×10-14m/W,五阶非线性吸收系数γ=2.7×10-28m3/W2,属于双光子吸收诱导激发态吸收。BTAB作为一种有用的非线性光学(NLO)候选材料具有潜在应用前景。  相似文献   

10.
卫永第  刘亚娇 《分析化学》1994,22(3):308-310
本文测定了中国雪参根中人参挥发油的含量,并用色谱-质谱联用仪分析了化学成分及百分含量。从中分离出132种化合物,初步鉴定出49种,占挥发油总量的87.73%,有28种化合物尚未见报道。  相似文献   

11.
为了解重庆市抽样地区自然环境中的碘含量,为碘盐的合理摄入和防治碘相关疾病提供依据,采用多级整群随机抽样法,选择重庆市渝东地区云阳县和渝西地区璧山县为调查点,在两县经济状况中等的乡镇各抽取3所乡镇小学的8~10岁儿童各30名作为调查对象,以直接滴定法(GB/T13025.7-1999)检测了其家庭食用盐碘含量;采用随机抽样方法抽取两县居民饮用水样和土壤样,以GB5750-85中砷铈催化分光光度法测定了水碘含量,反向放大比色法测定了土壤碘含量。结果表明,检测两县居民食盐样本556份,璧山县与云阳县食盐碘均数分别为30.41和35.78mg/kg;抽取两县居民饮用水样87份,两县水碘中位数分别为6.50和2.78μg/L;水碘含量10μg/L的水样分别占73.33%和100%;抽取两县浅表层土壤样品88份,两县土壤碘中位数分别为8.20和7.56mg/kg。提示两抽样县均属于碘缺乏地区,需要通过食盐加碘防治碘缺乏病。可根据各地区具体情况,考虑适当调整食盐含碘量。  相似文献   

12.
Twelve powdered and 13 liquid infant formulas were analyzed by using an extension of AOAC Official Method 996.01 for fat analysis in cereal products. Samples were hydrolyzed with 8 N HCl and extracted with ethyl and petroleum ethers. Fatty acid methyl esters were prepared by refluxing the mixed ether extracts with methanolic sodium hydroxide in the presence of 14% boron trifluoride in methanol. The extracts were analyzed by gas chromatography. In powdered formulas, saturated fatty acid (SFA) content (mean +/- SD; n = 12) was 41.05 +/- 3.94%, monounsaturated fatty acid (MUFA) content was 36.97 +/- 3.38%, polyunsaturated fatty acid (PUFA) content was 20.07 +/- 3.08%, and total trans fatty acid content was 1.30 +/- 1.27%. In liquid formulas, SFA content (mean +/- SD; n = 13) was 42.29 +/- 2.98%, MUFA content was 36.05 +/- 2.47%, PUFA content was 20.65 +/- 2.40%, and total trans fatty acid content was 0.88 +/- 0.54%. Total fat content in powdered formulas ranged from 4.4 to 5.5 g/100 kcal and linoleic acid content ranged from 868 to 1166 mg/100 kcal. In liquid formulas, total fat content ranged from 4.1 to 5.1 g/100 kcal and linoleic acid content ranged from 820 to 1100 mg/100 kcal. There were no significant differences between powdered and liquid infant formulas in concentrations of total fat, SFA, MUFA, PUFA, or trans fatty acids.  相似文献   

13.
A model low-fat salad dressing including salep as thickening agent was prepared. In order to obtain an stable salad dressing, different variables each one at three levels like salep content (0.5, 2.0, and 3.5% w/w), oil volume fraction (7.50, 16.25, and 25.00% w/w), pH (3, 5, and 7), salt concentration (0.3, 0.9, and 1.5% w/w), and egg yolk content (2, 4, and 6% w/w) were chosen and their effect on the creaming index of salad dressing was studied. It was observed that samples with highest salep content at pH 3 were the most stable during storage time (15 days). The microstructure of some samples was considered. Rheological measurements were performed for stable samples. Oil fraction and salt content increased zero shear viscosity and G′ modulus of samples.   相似文献   

14.
对气相色谱-热能分析联用法测定卷烟主流烟气总粒相物中NNK含量的测量不确定度进行评定,分析了NNK含量检测的影响因素,计算了不确定度分量及合成不确定度,当NNK含量测定结果为27.4ng/支时,扩展不确定度为2.0ng/支。  相似文献   

15.
The phase diagrams of S1570–Brij 97/oleic acid/water system at two different S1570/Brij 97 mass ratios of 1/1 (system S) and 7/3 (system P) were determined at 37°C, respectively. The microstructures and rheological properties of liquid crystals at constant surfactants/water mass ratio of 1/1 were studied with increase in oil content. Small-angle x-ray scattering measurements showed that system S exhibited a typical lamellar liquid crystals and the repeat distance (d) decreased as oil content increased. While for system P, two couples of scattering peaks were observed when oil content reached 28 wt%. This indicated that adding oil content may give rise to a multilamellar structures in the higher S1570/Brij 97 mass ratio system. The rheological tests indicated that a transition from elastic gel-like properties to viscoelastic liquid-like properties appeared in both system S and P when oil content reached 20 wt%, corresponding to the polarizing optical microscopy textures changing from oily streak to cruciate flower. This supplies a way to adjust structure, rheological properties, and even phase transition by altering the S1570/Brij 97 mass ratio and oleic acid content in system.  相似文献   

16.
合成条件对TS-1结构及其催化氯丙烯环氧化的影响   总被引:1,自引:0,他引:1  
周颖  王莅  米镇涛 《分子催化》2005,19(6):468-472
采用水热法合成了TS-1分子筛,根据XRD、FT-IR、FT-Raman和UV-Vis的表征结果计算了TS-1的相对结晶度和骨架钛相对含量,并以氯丙烯环氧化反应为探针反应,研究了合成条件对TS-1的结构和催化性能的影响,结果表明,TS-1的结晶度随合成液中Si/Ti比和TPAOH/Si比的增大呈先增大后减小的趋势,TS-1的骨架钛相对含量也随合成液中钛含量的减少呈先增大后减小的趋势,随TPAOH含量的增加TS-1的骨架钛相对含量和非骨架钛含量一直增加,且非骨架钛的类型有所改变.具有较高结晶度和骨架钛含量及较低非骨架钛含量的TS-1的催化性能较好.较好的氯丙烯的转化率和环氧氯丙烷的选择性分别为92.1%和87.5%.  相似文献   

17.
In this study, a syringe-connected minicolumn resin was used for the separation and enrichment of cadmium, copper, nickel and zinc prior to their determination by flame atomic absorption spectrometry. The proposed technique was compared with classical batch and column techniques in terms of rapidness, simplicity, enrichment and risk of contamination. The minicolumn was filled with Chromosorb-103 resin and connected to a syringe. If the samples were treated with ammonium pyrrolidine dithiocarbamate or 8-hydroxyquinoline, the analytes were quantitatively retained at pH2 and pH5 on the resin, respectively. On the other hand, if no chelating agent was added, the analytes were quantitatively retained at pH10. The analytes retained by the resin were quantitatively eluted by drawing and discharging nitric acid in acetone. The analytes in spiked river-water samples and in certified standard reference Bovine-Liver (NIST SRM 1577 b) were quantitatively (94%) recovered. The relative standard deviations for the determinations were found to be 1.0–10%.  相似文献   

18.
Organic–inorganic hybrids based on poly(vinyl alcohol) (PVA)/SiO2 hybrid membranes containing sulfonic acid groups were prepared using the sol–gel process under acidic conditions. The PVA/sulfosuccinic acid (SSA)/silica hybrid membranes were fabricated from different SSA contents. The proton conductivity and methanol permeability of the hybrid membranes were studied with changing SSA content from 5 to 25 wt.%. It was found that the proton conductivity and the methanol permeability were dependent on the SSA content both as a crosslinking agent, and as a donor of the hydrophilic SO3H group. Up to an SSA content of about 20 wt.%, both of these properties decrease, and above this SSA content, they begin to increase with increasing SSA content. The proton conductivities of the PVA/SSA/silica membranes were in the range of 10−3 to 10−2 S/cm, and the methanol permeabilities ranged between 10−8 and 10−7 cm2/s. The presence of silica particles in the organic polymer matrix, which reduce the free water ratio of the membranes, results in hybrids with markedly reduced methanol permeabilities. These characteristics of the PVA/SSA/silica hybrid membranes are desirable for future applications related to direct methanol fuel cells.  相似文献   

19.
The interactions of nabumetone (NAB) with -cyclodextrin (-CD) and-cyclodextrin (-CD) were studied in aqueous solution by meansof phase-solubility analysis. Solid dispersions of NAB with -cyclodextrin(-CD), -cyclodextrin (-CD), methyl- (M-CD),hydroxypropyl-cyclodextrin (HP-CD) were prepared by coevaporationand kneading and also by coprecipitation in the case of -CD. X-ray diffractometry, thermal analysis and infrared spectroscopy (FTIR) were used to study the possibility of complexation of the drug with the different cyclodextrins. Solid dispersions of nabumetone with -CD showed a remarkable improvement in the dissolution rate of nabumetone.  相似文献   

20.
以PVC,TPU为主要原料,加入发泡剂AC,交联剂DCP,空心玻璃微珠及其他助剂经模压成型制备了PVC/TPU轻质材料.通过密度以及机械性能测试研究了TPU用量、DCP用量和空心玻璃微珠含量对PVC/TPU轻质材料性能的影响,用红外光谱研究材料基团的变化,通过凝胶含量测试交联体系凝胶量,用SEM扫描电镜表征了材料的泡孔形状、尺寸以及排列.聚酯型TPU能够提高轻质材料弯曲和冲击强度,TPU加入10份时,共混体系的表观密度最低,为0.30 g/cm3.表观密度随着交联剂DCP的添加先降低后增大,红外表征和凝胶含量测试证实轻质材料体系产生了交联结构.空心玻璃微珠的加入,使得PVC/TPU轻质材料的表观密度和综合机械性能提高明显,即使加入20份空心玻璃微珠密度始终小于1.0 g/cm3.SEM表明,DCP的加入使得泡孔更完整且不易破孔,泡孔壁更厚;空心玻璃微珠分布在泡孔壁上,起到引发泡孔和支撑负荷的作用.  相似文献   

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