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1.
建立了超高效液相色谱-串联质谱快速检测保健食品中10种禁用激素类的方法。样品经乙腈超声提取,基质分散固相萃取法净化,用Thermo Hypersil Gold色谱柱分离,采用三重四级杆质谱进行定性及定量分析。结果表明:10种禁用类激素在1-1000μg/L范围内线性关系良好,检出限为0.3-0.5μg/kg,在低、中、高3个添加水平范围内的平均回收率为71.4%~113.5%之间,相对标准偏差为2.1%-13.6%。该方法分析时间短,灵敏度高,定性定量准确,适用于保健食品中非法添加激素类物质的检测。  相似文献   

2.
利用超高效液相色谱-串联质谱,建立了水中五氯酚的定量分析方法.该方法不需要浓缩,样品经0.45μm微孔滤膜过滤后,直接进样超高效液相色谱-串联质谱分析.目标物的回收率为78%~110%,在1.0~200μg/L范围内,有很好的线性相关性,方法的检出限为0.01μg/L.结果表明该方法具有灵敏度高,操作简单、快速的优点.  相似文献   

3.
研究建立吹扫捕集-气相色谱质谱法测定水中痕量甲基叔丁基醚(MTBE)的方法.以氘代甲苯为内标物,此方法的检出限(MDL)为0.005μg/L,线性相关系数R为0.999 8,精密度RSD范围0.87%~1.63%,加标回收率范围92.6%~98.9%.该方法快速、简单,干扰较少,样品需求量少,结果准确、可靠,重现性好,检出限低,实用价值高,适用于水中痕量甲基叔丁基醚的测定.  相似文献   

4.
开发一种分析2-去氧-D-葡萄糖样品的离子色谱方法,该方法可准确定量2-去氧-D-葡萄糖样品的含量.经色谱分离条件优化,选用DIONEX CarboPac PA10(4 mm×250 mm)色谱柱,以18 mmol/L NaOH溶液为流动相,流速为0.8 mL/min,用脉冲安培检测器检测,实现2-去氧-D-葡萄糖、葡萄糖和氨基葡萄糖3种结构极为相似单糖的高效分离,建立起2-去氧-D-葡萄糖的离子色谱法.2-去氧-D-葡萄糖在0.618~61.8μg/mL范围内呈现良好的线性关系,相关系数为0.998 6,最低检测限为27.2μg/L,最低定量限为216.3μg/L,平均回收率101.3%,实验结果表明该离子色谱法检测2-去氧-D-葡萄糖,简单、灵敏,测定结果准确,是测定2-去氧-D-葡萄糖含量的有效方法.  相似文献   

5.
建立一种用反相高效液相色谱法同时测定蜂王浆口服液中5-羟甲基糠醛和10-羟基- 2-癸烯酸的方法。样品经 0.01 mol/L 的盐酸溶液和甲醇溶解并沉淀蛋白后提取。采用 C18 柱 (250 mm×4.6 mm,5 µm)分离,以甲醇(55%)+0.01 mol/L盐酸溶液(45%)为流动相,流速为1.0 mL/min, 检测波长为280 nm(5-羟甲基糠醛)及 210 nm(10-羟基-2-癸烯酸),以出峰时间定性,以外标法定 量。结果表明,该方法的检出限及定量限均为 5 mg/kg,线性范围为 0.5~20.0 µg/mL。同时测定 5-羟甲基糠醛和 10-羟基-2-癸烯酸方法的相关系数分别为 0.999 97 和 0.999 95,回收率分别为 89.4%~103.0%和88.9%~102.0%。  相似文献   

6.
气相色谱-质谱法测定鱼肉中丁香酚的残留   总被引:3,自引:0,他引:3       下载免费PDF全文
研究建立一种鱼肉中丁香酚(eugenol)残留量的固相萃取-气相色谱-质谱检测方法.样品采用正己烷提取,硅胶柱净化,乙酸乙酯洗脱,气相色谱-质谱测定,内标法定量.丁香酚的响应值与其质量浓度在0.005~0.5 mg·L-1范围内的线性关系良好,相关系数为0.999 8;10~200μg·kg-1添加浓度的日内和日间平均回收率为80.6%~93.2%,相对标准偏差为3.47%~8.47%;检出限为5μg·kg-1,最低定量限为10μg·kg-1.该方法适用于鱼肉中丁香酚残留的检测.  相似文献   

7.
建立了调味料中4-甲基咪唑(4-MI)的毛细管气相色谱/氢火焰离子化检测器(GC-FID)的检测方法,采用DB-Innowax毛细管柱,样品经2,mL水溶解、乙醇定容后直接进气相色谱仪分析。实验结果表明:直接使用有机溶剂萃取的4-甲基咪唑回收率偏低,其最低检出限为0.02,mg/kg,加标回收率达到95%以上。方法首次采用乙醇、水混合溶液作为萃取溶剂,具有简便、快速、回收率高的优点,可应用于市售调味料中4-甲基咪唑的检测。  相似文献   

8.
优化的原子荧光法测定砷汞含量   总被引:1,自引:0,他引:1  
建立了用AFS-830双道原子荧光光度计同时测定不同样品中砷和汞的氢化物发生-原子荧光法检测方法.在优化的仪器工作条件下:砷和汞的线性检测范围广,分别为0~10μg/L和0~1μg/L;方法灵敏,检出限分别为0.042μg/L和0.038μg/L;样品加标回收率高,分别为99.5%~100.1%和97.5%~99.9%,可用于工业环境监测中测定不同样品中的砷和汞的含量.  相似文献   

9.
建立了一种用于分离2,4-二氯-5-甲基吡啶和2-氯-4-硝基-5-甲基吡啶的HPLC分析方法.液相色谱使用ODS-C18柱,以甲醇水=8020为流动相,紫外检测波长为254 m.样品线性范围50~500μg/mL.该法准确、快速、简便,可用于实际生产中间控制.  相似文献   

10.
建立用微波消解荧光光度法测定奶粉中微量硒的方法。利用Se与I-反应形成的I2对6-甲基-2-(α-羟甲基)-1H-苯并咪唑(MHMB)的荧光淬灭作用,在λex/λem=278/597nm的条件下测定MHMB的荧光强度。结果表明,当KI和MHMB的加入量分别为0.1mL和2.0mL时,硒的检出限0.17μg/L,线性范围(0.34~5.0)μg/L,样品测定的RSD为2.54%(n=6),回收率为95.7%~104%。方法灵敏度和准确度高,测定结果满意。  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

16.
17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

19.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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