共查询到20条相似文献,搜索用时 250 毫秒
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鸦片的气相色谱快速分析 总被引:2,自引:0,他引:2
采用大口径毛细管柱,建立了一种气相色谱测定鸦片中生物碱的快速分析方法。样品经超声提取,HP-1(5m×0.53mm×2.65μm)毛细管色谱柱,FID测定。回收率为96.8% ̄101.1%,相对标准偏差均小于3%。方法简便,快速,准确,灵敏。 相似文献
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双动态吸附毛细管电色谱的手性分离——采用阳离子表面活性剂和阴离子手性选择剂作为假固定相 总被引:2,自引:2,他引:0
建立了以十六烷基三甲基溴化铵或1,5-二甲基-1,5-二氮杂十一烷亚甲基聚N-甲溴化物为阳离子表面活性剂,并以磺丁基β-环糊精为手性选择剂的双动态吸附毛细管电色谱。以碱性的丙比胺和酸性的华法林作为拆分对象,考察了双动态吸附毛细管电色谱的手性分离行为,以及动态吸附柱的重复性。在双动态吸附毛细管电色谱条件下,丙比胺和华法林的手性分离度较大,丙比胺的分离度可达3.21,丙比胺连续进样10次,迁移时间的相对标准偏差小于1.0%。 相似文献
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《分析测试技术与仪器》1998,4(2):127-127
新型碳分子筛毛细管色谱柱中国科学院兰州化学物理研究所色谱技术研究开发中心研究人员经过两年多的探索,成功地研制开发出碳分子筛石英毛细管气相色谱柱。经修饰改性的碳分子筛C-2000色谱柱能够一次进行分离H2、C2、N2、CO、CH4、CO2、C2H2、C... 相似文献
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Estimating the feasibility of acid gas geological disposal requires the knowledge of the water content of the gas phase at moderate pressures and temperatures (typically below 50 MPa, below 380 K) and up to 6 mol NaCl. In this paper, a non-iterative model is developed to predict the water content of sour and acid gases at equilibrium with pure water and brine. This model is based on equating the chemical potential of water and using the modified Redlich–Kwong equation of state to calculate the fugacity of the gas phase. The water content of pure CH4, CO2 and H2S are represented with average absolute deviations of less than 3.36, 7.04 and 8.4%, respectively. Experimental data of the water content of mixtures of the acid gases were reproduced with average absolute deviations of less than 6.32%. 相似文献
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甲基安非他明及杂质的气相色谱/质谱分析 总被引:5,自引:0,他引:5
利用DB-5弹性石英毛细管柱气相色谱/质谱联用技术分析公安人员缴获非法生产甲基安非他明粗产品,其中含有甲基安非他明83%,及主要杂质1-苯基丙酮13.36%和2-甲亚胺基-1-基基丙烷1.33%。此外还检测到 了甲基安非他明的分解产物1-丙烯基苯0.11%、2-丙烯基苯0.03%和环丙基苯0.01%等。据此我科可以判断,该甲基安非他明是从1-苯基丙酮和甲胺反应再经催化氢化合而得。 相似文献
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Koskinen-Soivi ML Leppämäki E Ståhlberg P 《Analytical and bioanalytical chemistry》2005,381(8):1625-1630
Nitrogen-containing fuels produce hydrogen cyanide when the fuel is gasified. The gas is poisonous and produces nitrogen oxides when it is burned. HCN is usually sampled into alkaline solutions and analysed using an ion selective electrode. The method is tedious and the electrode response is temperature-dependent. Samples are not stable and must be analysed immediately, and they contain ions which are poisonous to the electrode. Therefore a new gas chromatographic method was developed. In this new method HCN is released from the alkaline solutions with sulphuric acid in a headspace sampler and analysed by a gas chromatograph connected to an atomic emission detector. Measurements on carbon emission line 193.1 nm gave the limit of detection 0.05 mg CN–/l in the solution. The calibration curve was linear to 1000 mg CN–/l and the correlation was 0.997. The relative standard deviation of the calibration was 1.7% at the concentration of 5 mg CN–/l and 1.0% at 25 mg CN–/l. The developed headspace method allows automated analysis and it needs less sample preparations than the ion selective electrode method. This paper also reports the effect of sample preparation and storage time on the stability of the samples. 相似文献
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气相色谱法快速测定空气中低分子量醛 总被引:6,自引:0,他引:6
用填充气相色谱直接进样法测定了污染空气中甲醛、乙醛、丙醛的含量,并对方法的灵敏度、准确度及各种影响因素进行了探讨。方法用于样品测定取得了较为满意的结果。 相似文献
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P. Englezos N. Kalogerakis P. R. Bishnoi 《Journal of inclusion phenomena and macrocyclic chemistry》1990,8(1-2):89-101
Based on our theoretical and experimental work carried out during the last decade, our understanding of the thermodynamics and the kinetics of formation and decomposition of gas hydrates is presented. Hydrate formation is modelled as a crystallization process where two distinct processes (nucleation and growth) are involved. Prior to the nucleation the concentration of the gas in the liquid water exceeds that corresponding to the vapor-liquid equilibrium. This supersaturation is attributed to the extensive structural orientation in the liquid water and is necessary for the phase change to occur. The growth of the hydrate nuclei or the decomposition of a hydrate particle are modelled as two-step procedures. Only one adjustable parameter for each hydrate forming gas is required for the intrinsic rate of formation or decomposition. In addition the inhibiting effects of electrolytes or methanol on hydrate formation are discussed and experimental data on methane gas hydrate formation in the presence of aqueous solutions of 3% NaCl and 3% NaCl + 3% KCI, are presented along with the predicted values. Finally, the relevence of the ideas to the technological implications of gas hydrates as well as areas where future research is needed are discussed.Dedicated to Dr D. W. Davidson in honor of his great contributions to the sciences of inclusion phenomena. 相似文献
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This paper compares three methods for natural gas dehydration that are widely applied in industry:(1) absorption by triethylene glycol, (2) adsorption on solid desiccants and (3) condensation. A comparison is made according to their energy demand and suitability for use. The energy calculations are performed on a model where 105 Nm3/h water saturated natural gas is processed at 30 °C. The pressure of the gas varies from 7 to 20 MPa. The required outlet concentration of water in natural gas is equivalent to the dew point temperature of -10 °C at gas pressure of 4 MPa. 相似文献
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Adissu Alemayehu Asfaw Matthias Van der Veken Kris Wolfs Ann Van Schepdael Erwin Adams 《Journal of separation science》2019,42(17):2816-2825
Reference introduction in thermal desorption with gas chromatography is a critical aspect. It is mostly performed by offline liquid calibration using a micro syringe to inject a liquid standard solution on the sorbent in the thermal desorption tube. This is based on the assumptions that the adsorption‐desorption process is quantitative and that no sample is lost in manipulating the tube. However, for analytical procedures involving thermal extraction of solid matrices, the adsorption‐desorption processes for sample and reference differ and the assumptions are not always fulfilled. This is explored in this work. First, issues related to the online liquid calibration were investigated. With tubes containing only quartz filters, a relative loss of over 80% was noticed for some solvents due to tube manipulation processes. Enclosing a bed of mesoporous silica as sorbent limited the losses to about 25% when samples were immediately analysed, and even better results were obtained when tubes were stored for several hours so that proper adsorption could take place. An additional sweep gas during loading boosted the transfer of analytes with recoveries above 95%. Next, an inline injection system was installed on the thermal desorber instrument. This sorbent free, independent calibration tool avoids the drawbacks of other approaches. 相似文献
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改用氢火焰离子化检测器和毛细管色谱柱,以医用100 mL输液瓶为气液平衡瓶,采用带锁定气密性注射器,利用顶空气相色谱法对茶多酚工业废水中三氯甲烷含量进行了测定,通过实验得到最佳顶空色谱条件。结果表明,以SPETM-1毛细管色谱柱,FID检测器进行顶空气相色谱测定,标准曲线相关系数为0.9997,RSD为2.73%~5.16%之间,回收率在99.28%~99.98%之间,方法精密度好,准确度高,能满足工业分析要求。 相似文献