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1.
采用动态微波辅助顶空固相微萃取结合气相色谱-质谱法测定芹菜叶中的挥发性和半挥发性化学成分。对水蒸气蒸馏、顶空固相微萃取、微波辅助顶空固相微萃取、动态微波辅助顶空固相微萃取等4种不同的前处理方法进行了比较,通过气相色谱-质谱分析,分别鉴定出20,17,36,41种化学成分,主要化合物为α-月桂烯、柠檬烯、β-顺式罗勒烯、β-芹子烯和(Z)-3-己烯-1-醇等。结果表明:动态微波辅助顶空固相微萃取是一种简单、快速、易操作,无需净化步骤,消耗样品量少,对于沸点较高的半挥发性物质的萃取效果优于微波辅助顶空固相微萃取的方法,可用于分析各类植物中的挥发性和半挥发性化学成分。  相似文献   

2.
微波辅助萃取/样品前处理联用技术的研究进展   总被引:1,自引:0,他引:1  
微波辅助萃取是近年来新发展的一种样品前处理技术,随着微波辅助萃取的发展和成熟,它与其它样品前处理技术的联用得到了迅速发展。与传统前处理方法相比,这些联用方法具有快速、高效、操作简便、节省溶剂、选择性好、应用范围广的特点。该文综述了微波辅助萃取及其与其它样品前处理技术联用的特点及适用性,并对近年来微波辅助萃取与其它前处理方法联用的发展概况及在分析领域中的应用情况进行了详细总结。  相似文献   

3.
绿色分析化学技术进展   总被引:2,自引:1,他引:2  
绿色分析化学技术是国际分析化学的前沿,受到广泛关注.绿色分析化学是把绿色化学的原理使用在新的分析方法和技术方面.目前的研究主要集中在环境友好的样品前处理技术(如微波消解、微波萃取、固相萃取、固相微萃取、超临界流体萃取等)和绿色分析测试技术(如X射线荧光分析法、近红外技术、毛细管电泳、顶空气相色谱等).文章对上述内容进行了综述.  相似文献   

4.
该文主要综述了油料油脂酚类化合物测定中的样品前处理技术研究进展,包括液液萃取、超声波辅助萃取、微波辅助萃取、超临界流体萃取、固相萃取以及磁固相萃取等。比较了不同前处理技术的优缺点,并对油料油脂酚类化合物测定中样品前处理技术研究趋势进行了展望。  相似文献   

5.
作为与人们日常生活紧密相关的消费品之一,化妆品中禁、限用成分的分析检测,对于监控化妆品质量、保证消费者使用安全具有重要的研究意义。由于化妆品基质复杂,基体干扰严重,难以对目标物进行直接检测,因此需要采用样品前处理技术对其进行分离富集。该文综述了近年来的化妆品样品前处理方法,包括消解法、液-液萃取、固相萃取、固相微萃取、液相微萃取技术、微波辅助萃取以及超声波辅助提取等,并对其发展方向进行了展望。  相似文献   

6.
生物检材中氯胺酮及其代谢物的分析方法研究进展   总被引:1,自引:0,他引:1  
综述了生物检材中氯胺酮及其代谢物分析技术的进展,评述了液相萃取、固相萃取、固相微萃取、顶空固相微萃取、微波辅助萃取等技术在分析中的应用,以及薄层色谱、气相色谱、高效液相色谱、毛细管电泳及其联用检测技术、酶联免疫分析技术和太赫兹时域光谱等检测技术在分析生物检材中氯胺酮的优势和局限性,并展望了该领域研究的发展趋势.  相似文献   

7.
农药残留分析的样品来源多样、基体复杂,而传统的离线样品前处理中,萃取、转移、净化、浓缩等步骤分步进行,繁琐费时、样品损失较大、精密度和重现性差,因此,发展样品前处理-色谱在线分析技术可望解决这些问题。本文综述了近年来固相萃取、固相微萃取、基质固相分散萃取、膜萃取、微波辅助萃取、加速溶剂萃取和超临界萃取等样品前处理-色谱在线分析农药残留的研究进展,并展望了其应用前景和发展方向。引用文献54篇。  相似文献   

8.
杨吉娜  刘丹阳  周婷 《色谱》2020,38(1):74-85
脂质作为细胞膜和亚细胞膜的主要结构成分,在能量来源、细胞信号传导等多种生物学过程中发挥着重要作用。近年来,脂质分析受到越来越多的关注,其中色谱-质谱联用技术在脂质分析中占据主导地位。由于样品基质复杂,样品前处理有富集痕量物质和减少基质干扰的作用,成为脂质分析中的一个关键步骤。该文综述了近年来基于色谱-质谱联用技术的脂质分析中样品前处理技术的研究进展和应用,对各种样品前处理技术进行了阐述和总结。基于液相的萃取方法有液-液萃取和单一有机溶剂萃取。基于固相的萃取方法包括固相萃取和固相微萃取。场辅助萃取方法包括超临界流体萃取、加压流体萃取、微波辅助萃取和超声辅助萃取。此外,还介绍了在线联用样品前处理方法和用于活体分析的样品前处理方法。最后,对基于色谱-质谱联用的脂质分析样品前处理技术存在的问题及发展趋势进行了探讨。样品前处理技术的发展将提高脂质分析的灵敏度、选择性和分析速度。  相似文献   

9.
建立了微波辅助-微固相在线萃取/气相色谱-质谱联用(GC-MS)测定污泥中19种多氯联苯(PCBs)含量的分析方法。对微波辅助-微固相在线萃取条件进行优化,得出最优萃取条件为:萃取温度60℃,萃取时间25 min,解吸溶剂为乙酸乙酯,解吸剂用量150μL,解吸时间25 min。在优化条件下,方法的检出限为0.2~2.5 ng/g,相对标准偏差(RSD)小于14%,回收率为81.4%~102.1%。与传统的微波萃取、微固相萃取、超声萃取等方法相比,该方法集萃取、净化和浓缩于一体,极大地缩短了分析时间,适合于复杂环境样品体系中痕量PCBs的分析检测。  相似文献   

10.
《色谱》2020,(1)
脂质作为细胞膜和亚细胞膜的主要结构成分,在能量来源、细胞信号传导等多种生物学过程中发挥着重要作用。近年来,脂质分析受到越来越多的关注,其中色谱-质谱联用技术在脂质分析中占据主导地位。由于样品基质复杂,样品前处理有富集痕量物质和减少基质干扰的作用,成为脂质分析中的一个关键步骤。该文综述了近年来基于色谱-质谱联用技术的脂质分析中样品前处理技术的研究进展和应用,对各种样品前处理技术进行了阐述和总结。基于液相的萃取方法有液-液萃取和单一有机溶剂萃取。基于固相的萃取方法包括固相萃取和固相微萃取。场辅助萃取方法包括超临界流体萃取、加压流体萃取、微波辅助萃取和超声辅助萃取。此外,还介绍了在线联用样品前处理方法和用于活体分析的样品前处理方法。最后,对基于色谱-质谱联用的脂质分析样品前处理技术存在的问题及发展趋势进行了探讨。样品前处理技术的发展将提高脂质分析的灵敏度、选择性和分析速度。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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