首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
分光光度计测铁矿石中钛的测量不确定度评定   总被引:1,自引:0,他引:1  
紫外-可见分光光度计在化学分析中应用较为广泛。对于借助其进行化学分析测量不确定度的评定,目前较多见于溶液测定。实际应用中,测试样品多为固体,涉及到称样、溶解、稀释、定容等步骤。此文试从随机效应和系统效应的角度考虑,对紫外-可见分光光度计应用ISO4691:1985铁矿石中钛含量的测定——二安替比林甲烷分光光度法对铁矿石中钛的测量过程中的不确定度来源进行了较为全面的分析,并最终给出评定结果。  相似文献   

2.
以商品三棱中20种宏量及微量元素的含量为分类特征,用非线性映照法对32个样品进行了鉴别分类,准确地区分了药典规定的正品三棱和非正品三棱,所得结果与生药学鉴定完全一致,为中药鉴定提供了一种全新的方法。  相似文献   

3.
气相色谱法快速鉴定植物油   总被引:4,自引:1,他引:3  
田文荣  余仲建 《色谱》1990,8(6):393-394
分析植物油的经典方法是测定多种物理常数和进行化学分析。方法十分烦杂,费时费事,结果还不一定可靠,特别是鉴别伪劣品更困难。本文用气相色谱法快速鉴定国内常见的十三种植物油。试样经甲酯化后用φ2mm×1m 5%Reoplex 400柱在15min内就能很好地分离月桂酸、肉豆蔻酸、软脂酸、油酸、亚油酸、亚麻酸、花生烯酸和芥酸的甲酯。提出以脂肪酸甲酯作为保留指数的基准物,测  相似文献   

4.
金红石是生产TiCl_(4)的主要原料,TiCl_(4)是生产海绵钛的主要原料,金红石中杂质元素的含量决定着钛及钛合金产品的质量。目前,分析金红石多采用滴定法、重量法、分光光度法、火焰原子吸收光谱法等,具体见YS/T 514《高钛渣、金红石化学分析方法》系列。但上述方法存在前处理较复杂、分析周期长、每次只能测定一个元素等问题,不适用于金红石中多种杂质元素的快速分析。  相似文献   

5.
李辽沙  隋智通 《化学通报》2001,64(7):439-442
本文用EMF及化学分析方法研究了富钛(25(wt)%TiO2)氧化物熔渣体系中低价钛氧化的动力学规律,探讨了添加铁氧化物对改善熔渣氧传输动力学条件的机制,及渣中低价钛的氧化与相关耦合反应的关系。  相似文献   

6.
虎纹捕鸟蛛毒中次黄嘌呤核苷的分离与鉴定   总被引:3,自引:0,他引:3  
佘益民  梁宋平 《分析化学》1995,23(9):1081-1083
本文从虎纹捕鸟蛛粗毒中经高效液相色谱分离纯化出一种组分,通过场解吸质谱和电子电离质谱鉴定为次黄嘌呤核苷,其含量为3.9%。同时,进一步用标准样品进行紫外、液相色谱对照验证,并对次黄嘌呤核苷以毒液中的一种成分的形式存在的作用进行了简单的讨论。  相似文献   

7.
光度法测定催化剂中钛   总被引:1,自引:0,他引:1  
二氧化钛是继二氧化硅、三氧化二铝之后的第三代催化剂载体。长期以来,工业上的加氢脱硫催化剂都是以γ-Al2O3为载体,而用二氧化钛作载体的催化剂活性高,低温性能好,抗中毒性强,抗结碳性比以三氧化二铝为载体的催化剂高10倍。钛作为催化剂的基体元素,在研制、生产和使用过程中,均需严格控制和准确测定其含量。光度法测定钛是比较常见的方法,广泛用于测定铝合金、合金钢中钛,而对催化剂中钛含量测定报道较少。本方法在聚四氟乙烯压力溶弹内,用王水溶解样品,具有溶剂用量少,免受污染等优点。以铬变酸作为显色剂,光度法测定催化剂中钛,得到了满意结果。  相似文献   

8.
刘颖  刘跃 《分析化学》2003,31(10):1228-1231
用气相色谱/质谱联用技术对红收获蚁Pogonomyrmex barbatus和Pogonomyrmex maricopa的杜氏腺体(Dufour gland)细胞壁的化学成分进行了鉴定。结果表明:其杜氏腺体的主要成分是烃类化合物。根据红收获蚁Dufour腺体的气相色谱,质谱的谱图,讨论了生物种属的气相色谱/质谱化学分类的可能性。研究表明:同一物种的生物体给出的图谱有一一对应的直观样式,生物组织化学成分的鉴定是生物化学分类的关键,相对峰高或峰面积百分含量不易表征图谱样式。  相似文献   

9.
将固体进样装置与电感耦合等离子体发射光谱仪(ICP-SSEA)联用,采用固体进样,直接测定铸铝合金中的铜、铁、镁、锰、镍、钛、硅、锌等元素含量。研究表明,该法与火花光谱法比较,具有很宽的的动态范围,测量精度和普通化学分析方法相当,同时又有火花光谱分析的速度。能满足工厂冶炼控制的要求。  相似文献   

10.
用化学和机械合金化两种方法将Y2O3复合到铁素体不锈钢粉中,经热等静压后制成氧化物弥散增强(ODS)铁紊体不锈钢,研究了其中的氧化物相的结构和成分与这两种复合方法的关系。结果表明,采用化学法的钢中复合相主要存在Y2Ti2O7相,而机械法钢中复合相主要存在Y2O3相;两种复合工艺制备的ODS钢中氧化物的钛含量有明显差异,而钇含量则与复合工艺关系不大。  相似文献   

11.
Due to the complexity of the chemical constitution of traditional Chinese medicines (TCMs), now there is a trend to establish methods, using multi-components analysis, for the effective quality control of TCMs. However, the limited availability of multiple reference substances hinders the wide popularization for routine quality control of TCMs. Using an easily available single component contained in the analyte as an internal standard to determine multiple analogues should be a practical option. In this study, we selected rhubarb rhizome as an example, and used emodin, the easily available active component, as the external standard to determine directly the content of emodin in rhubarb, and the same component as the internal standard to simultaneously determine the other six anthraquinones in rhubarb. Compared with the results obtained using the external standard method, this alternative method was found to have no statistically significant differences in our laboratory as verified by the F-test (p = 95%, n = 6). However, due to weak robustness caused by the fluctuation of relative response factors in different laboratories, such a method can only serve as a practical measure to solve the lack of so many chemical standard substances when relative response factors have been determined. This alternative method can then be used without reference substances. Once the corresponding chemical standards are available and are acceptable as well as cost-effective, then the external standard method for the simultaneous determination of multiple components (SDMC) in TCMs will prevail.  相似文献   

12.
《Arabian Journal of Chemistry》2020,13(10):7274-7288
It was for the first time that the complex compound of gallic acid with titanium (IV) salt was used as a precursor to synthesize titania nanotubes. The study was separated into four main sections; (I) synthesizing the complex of titanium with gallic acid, (II) synthesizing anatase and rutile phases through thermal decomposing of the complex, (III) investigating the possibility to synthesize titania nanotubes from the rutile and anatase phases, and (IV) photocatalytic ability of all the nanoparticles.Different methods were applied to analysis, including X-ray diffraction, 1H NMR, FT-IR spectroscopy, elemental analysis, quantum-chemical modeling, Raman spectroscopy, thermal analysis, photoluminescence, BET analysis (to investigate the specific surface activity, total pore volume), EDX, electron microscopy (SEM), acceleration voltages, electrical conductivity, BJH method (to determine average pore diameter), and UV-Vis spectroscopy.We illustrated the possibility of the synthesis of the titania nanotubes from the anatase phase, while rutile phase was not turned to a tube shape.The photocatalytic ability of the obtained nanoparticles was tested by degrading bromophenol blue, as an organic pollutant, under weak light. TiO2 in the form of nanotubes could reduce the concentration of bromophenol blue to 82%, as well as the rutile phase - to 70%, and finally anatase as nan-spheres to 36%.  相似文献   

13.
5-Br-PADAP光度法是测钒钛磁铁矿中钒的主要方法之一。根据其分析过程的操作步骤确定了其影响因素。建立数学模型,并根据数学模型把不确定度分解为称样质量、溶液含量、钒标准工作曲线和重复测定引入的各不确定度,对影响测量结果的各个分量进行了分析评定和计算。结果表明,钒的标准工作曲线的建立是影响样品分析误差的重要因素。  相似文献   

14.
Possibility of forming titanium nitride by anodic polarization of the surface of titanium in water-containing organic electrolytes in the presence of NH4F at potentials of 2–14 V was demonstrated and substantiated. The method of cyclic voltammetry was used to study electrochemical processes in electrolytes based on ethylene glycol and glycerol. Results obtained in an analysis of the structural, chemical, and physicomechanical properties of the titanium nitride layers obtained in the study are presented.  相似文献   

15.
The basic conditions for the determination of niobium, titanium and zirconium with an argon plasma and a Hitachi UHF Plasma Spectrascan operated at 2450 MHz and 450 W maximum output, have been established. The niobium 405.89-nm, titanium 365.35-nm and zirconium 339.19-nm lines gave detection limits of 0.5, 0.1 and 2.0 p.p.m., respectively, when pure solutions were used. Effects of gas flow rates, high-frequency output and concentration of acids were examined. In applications to steel, titanium was determined without prior chemical separation from iron at the 499.95-nm line, whereas niobium and zirconium could not be determined in the presence of large amounts of iron. When a cupferron precipitation method followed by extraction of iron with methyl isobutyl ketone was applied, satisfactory results were obtained.  相似文献   

16.
The basic conditions for the determination of niobium, titanium and zirconium with an argon plasma and a Hitachi UHF Plasma Spectrascan operated at 2450 MHz and 450 W maximum output, have been established. The niobium 405.89-nm, titanium 365.35-nm and zirconium 339.19-nm lines gave detection limits of 0.5, 0.1 and 2.0 p.p.m., respectively, when pure solutions were used. Effects of gas flow rates, high-frequency output and concentration of acids were examined. In applications to steel, titanium was determined without prior chemical separation from iron at the 499.95-nm line, whereas niobium and zirconium could not be determined in the presence of large amounts of iron. When a cupferron precipitation method followed by extraction of iron with methyl isobutyl ketone was applied, satisfactory results were obtained.  相似文献   

17.
Nickel–titanium alloys used in dentistry have a variety of mechanical, chemical, and biofunctional properties that are dependent on the manufacturing process. The aim of this study was to compare the mechanical and biofunctional performances of a nickel–titanium alloy produced by the continuous casting method (NiTi-2) with commercial nitinol (NiTi-1) manufactured by the classical process, i.e., from remelting in a vacuum furnace with electro-resistive heating and final casting into ingots. The chemical composition of the tested samples was analyzed using an energy dispersive X-ray analysis (EDX) and X-ray fluorescence (XRF). Electron backscatter diffraction (EBSD) quantitative microstructural analysis was performed to determine phase distribution in the samples. As part of the mechanical properties, the hardness on the surface of samples was measured with the static Vickers method. The release of metal ions (Ni, Ti) in artificial saliva (pH 6.5) and lactic acid (pH 2.3) was measured using a static immersion test. Finally, the resulting corrosion layer was revealed by means of a scanning electron microscope (SEM), which allows the detection and direct measurement of the formatted oxide layer thickness. To assess the biocompatibility of the tested nickel–titanium alloy samples, an MTT test of fibroblast cellular proliferation on direct contact with the samples was performed. The obtained data were analyzed with the IBM SPSS Statistics v22 software. EDX and XRF analyses showed a higher presence of Ni in the NiTi-2 sample. The EBSD analysis detected an additional NiTi2-cubic phase in the NiTi-2 microstructure. Additionally, in the NiTi-2 higher hardness was measured. An immersion test performed in artificial saliva after 7 days did not induce significant ion release in either group of samples (NiTi-1 and NiTi-2). The acidic environment significantly increased the release of toxic ions in both types of samples. However, Ni ion release was two times lower, and Ti ion release was three times lower from NiTi-2 than from NiTi-1. Comparison of the cells’ mitochondrial activity between the NiTi-1 and NiTi-2 groups did not show a statistically significant difference. In conclusion, we obtained an alloy of small diameter with an appropriate microstructure and better response compared to classic NiTi material. Thus, it appears from the present study that the continuous cast technology offers new possibilities for the production of NiTi material for usage in dentistry.  相似文献   

18.
主要概述了钒钛炉渣原料中价态钒(V2+,V3+,V4+,V5+),低价钛(Ti 2+,Ti 3+),金属钒(MV),氮化钒(VN),碳化钒(VC),碳化钛(TiC),氮化钛(TiN)及钢铁材料里固溶钒(Vsol),氮化钒(VN),碳化钒(VC),固溶钛(Tisol),碳化钛(TiC),氮化钛(TiN)等的化学物相分析的现状流程及最新进展,为从事钒钛化学物相分析方法研究者提供了参考依据。  相似文献   

19.
A new instrumental epithermal neutron activation analysis procedure to quantitatively determine titanium, barium, and bromine in obsidian with improved sensitivity has been developed. The advantage of epithermal activation for Ti, Ba, and Br is demonstrated with multiple geological standards and the ability to determine arsenic in obsidian is demonstrated. The results for titanium are compared to previous electron-microprobe results for Kenyan obsidian.  相似文献   

20.
Titanium nitride films were produced on silicon substrate by ion beam assisted deposition in the alternate mode: first, thin titanium layers were deposited by electron beam evaporation and then titanium nitride was formed by nitrogen implantation at room temperature; this cycle was then iterated many times in order to obtain thicker titanium nitride layers. The obtained films were characterized with respect to atomic composition by Rutherford backscattering spectrometry and nuclear reaction analysis techniques, while chemical bonding was investigated by Auger line-shape analysis. We observe that nitrogen implantation, along with the production of titanium nitride, induces silicon migration into the film. Silicon transport is connected to point defects produced by ion implantation as well as by chemical driving forces associated with silicides formation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号