共查询到20条相似文献,搜索用时 859 毫秒
1.
本文建立了人血中十种单端孢霉烯族毒素的气相色谱(电子捕获检测器)和气相色谱-质谱(气质)联用分析法。该法采用乙酸乙酯萃取血中毒素后,将萃取液浓缩至干,用七氟丁酰咪唑衍生化,用气相色谱和色/质联用分析测定。方法的最低检出限为1~10ng/mL血,回收率为60.8~101.1%。 相似文献
2.
3.
4.
5.
6.
气相色谱法分离检定血中八种氨基甲酸酯 总被引:5,自引:0,他引:5
采用国产C_18往固相提取血中八种氨基甲酸酯,用乙酸乙酯洗脱,用气相色谱分离检定,用气相色谱/质谱进行确证。此法灵敏度为1~2μg/mL血,最低检出限为20~40ng,回收率在62~92%之间。 相似文献
7.
毛细管气相色谱/原子吸收联用及大蒜油中痕量硒化学形态分析的研究 总被引:9,自引:0,他引:9
本文提出并建立了毛细管气相色谱/原子吸收联用(CGC/AAS)装置,并在此装置上建立了(CH3)2Se、(CH3)2Se2的分析方法。本方法的最小检测量分别为0.3ng和0.04ng。回收率分别为97%~105%和93%~110%,已用于大蒜油的实际样品分析,取得了满意的结果。 相似文献
8.
超临界流体萃取和气相色谱—质谱联用测定薄荷中有效成份 总被引:6,自引:1,他引:6
介绍用超临界流体萃取和气相色谱-质谱联用(SFE/GC-MS)法提取和测定薄荷中的有效成分,SFE的试验条件为:D:8-26MPa,温度:35-65℃,改性剂?:1%-10%乙醇,结果表明,在23MPa,55℃和7%极性剂条件下撮效率最佳,在此条件下其主成分薄荷醇的提取量为0.16%(W/W),比水蒸气蒸馏法提取量约高3倍,比有机溶剂法提取量约高0.6倍。 相似文献
9.
气相色谱质谱联用法对农产品中8种种衣剂农药残留的同时测定 总被引:2,自引:0,他引:2
应用气相色谱-质谱联用仪(GC-MS)建立了水果、蔬菜、粮谷等农产品中8种种衣剂农药残留的分析测定方法。样品用乙腈提取,通过石墨化碳或C18固相萃取小柱净化,经DB-5ms气相色谱柱分离,电子轰击电离(EI)、选择离子监测模式(SIM)对定量离子和定性离子进行MS测定。标准工作曲线范围0.02-0.5mg/L。样品中添加水平为0.005、0.010和0.020mg/kg时,回收率为74%~110%;相对标准偏差小于15%。检出限(S/N=3)为0.09~0.77μg/kg。 相似文献
10.
凝胶渗透色谱-气相色谱质谱法测定:花生中6种除草剂农药残留 总被引:1,自引:0,他引:1
建立了凝胶渗透色谱一气相色谱质谱(GPC~GC=MS)法测定花生中6种除草剂(氟乐灵、异恶草酮、甲草胺、二甲戊乐灵、乙氧氟草醚、喹禾灵)农药残留的方法。样品经乙腈提取,氨基固相萃取柱和凝胶渗透色谱净化,在选择离子扫描(SIM)模式下进行气相色谱质谱法测定,外标法定量。6种除草剂浓度在0.02-1.00mg/L范围内与色谱峰面积呈良好的线性,线性相关系数为O.9949~0.9998,添加回收率为77.8%-101.6%,测定结果的相对标准偏差为4.4%~11.4%(月=5),方法的检出限为0.1~1.3μg/kg。 相似文献
11.
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
12.
13.
电子鼻结合人工智能对呼出气进行检测、分析和识别已成为非侵入性医疗检测领域的研究热点。然而,目前已报道的气体传感材料尚不能同时满足高灵敏度、高选择性和稳定的室温检测,阻碍了气体传感器在医疗健康领域的应用及发展,寻找合适的传感材料具有重要的意义和挑战。新型二维层状纳米材料MXenes具有种类多、比表面积大、导电性能强、表面含有丰富的官能团以及能带宽度可调等优异性能,是高灵敏、低能耗气体传感器的明星候选材料。本综述针对MXenes基材料的特殊结构,总结梳理了MXenes基材料在气体传感中的最新研究成果,聚焦于MXenes材料的气体传感机理和改性方法,对MXenes材料用于气体传感依然存在的问题和挑战进行深入探讨。 相似文献
14.
本文采用低温气相色谱法分析了火焰气体的成份和深度,色谱柱固定相为PoraparkQ,柱温范围-99-250℃氦气作载气。在所选择的实验条件下,火焰气体中的N2和O2有效地得到分离,可迅速精确地分析确定N2的浓度以及其他成份和浓度。 相似文献
15.
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
16.
Catherine M. Zimmerman William J. Koros 《Journal of Polymer Science.Polymer Physics》1999,37(12):1235-1249
Despite efforts by the membrane community to develop polymeric materials with improved O2/N2 separation performance, limited progress has occurred for almost a decade. Molecular sieving media, which can exhibit gas separation properties superior to polymers, tend to be brittle and uneconomical to produce for large‐scale membrane separation processes. Considering this, the polymer structures investigated in this work were designed to mimic aspects of the structure of molecular sieving media such as zeolites and carbon molecular sieves while maintaining the processability associated with polymers. Significantly attractive gas separation material properties were obtained using hyper rigid polypyrrolone copolymers with controlled packing disruptions between flat, packable segments. The gas transport properties in the materials changed dramatically as a result of different average interchain spacing. Moreover, all of the polypyrrolones studied in this work exhibited performance lying on or above the existing O2/N2 upper bound trade‐off line between permselectivity and permeability. These results, therefore, may point the way to a new cycle of membrane materials improvements for gas separations. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1235–1249, 1999 相似文献
17.
A novel correlation for estimation of hydrate forming condition of natural gases 总被引:1,自引:0,他引:1 下载免费PDF全文
An inherent problem with natural gas production or transmission is the formation of gas hydrates, which can lead to safety hazards to production/
transportation systems and to substantial economic risks. Therefore, an understanding of conditions where hydrates form is necessary to
overcome hydrate related issues. Over the years, several models requiring more complicated and longer computations have been proposed for
the prediction of hydrate formation conditions of natural gases. For these reasons, it is essential to develop a reliable and simple-to-use method
for oil and gas practitioners. The purpose of this study is to formulate a novel empirical correlation for rapid estimation of hydrate formation
condition of sweet natural gases. The developed correlation holds for wide range of temperatures (265–298 K), pressures (1200 to 40000 kPa)
and molecular weights (16−29). New proposed correlation shows consistently accurate results across proposed pressure, temperature and
molecular weight ranges. This consistency could not be matched by any of the widely accepted existing correlations within the investigated
range. For all conditions, new correlation showed average absolute deviation to be less than 0.2% and provided much better results than the
widely accepted existing correlations. 相似文献
18.
气敏传感器已在生物、化学、航空、军事等领域获得了广泛的应用。鉴于WO3基气敏传感器是检测H2S、NOx、O3和NH3等气体最有前景的新型氧化物气敏传感器之一,本文以不同的敏感气体为分类依据系统阐述了近年来WO3基气敏传感器的研究进展,详细探讨了制备方法及贵金属掺杂对上述各种气体气敏性能的影响,并指出了目前WO3基气敏传感器在研究过程中存在的问题。 相似文献
19.