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1.
以新指示反应高敏催化光度测定痕量钌   总被引:3,自引:0,他引:3  
钌(Ru ̄Ⅲ)对高碘酸钾氧化无色孔雀绿的显色体系有催化作用,借此催化光度测Ru ̄Ⅲ,灵敏度高。在20~30℃下30~60min内,以1cm吸收池内测得吸光度0.1为可准确测极限,则可测最低浓度为0.08ng·mL ̄(-1),若表示为间接摩尔吸光系数则 =2.0×10 ̄8mol ̄(-1)·L·cm ̄(-1)。工作曲线线性范围为0.04~0.36ng/mL(室温约为26℃).其它贵金属如Os ̄Ⅷ、Rh ̄Ⅲ、Au ̄Ⅲ、Ag ̄Ⅰ、Pd ̄Ⅱ、Pt ̄Ⅳ等至少可允许分别存在200ng/mL、1ng/mL、200ng/mL、3000ng/mL、25ng/mL和5ng/mL。测定了含所有贵金属和某些其它常见金属人工混合液中的痕量Ru ̄Ⅲ,不含Ir ̄Ⅳ时回收率为98.5%~101.0%,含2.3倍于Ru ̄Ⅳ重量的lr ̄Ⅳ时回收率为101.5%~112%。  相似文献   

2.
提出了联苯胺-H2O2-辣根过氧化物酶(HRP)伏安酶联免疫分析体系测定植物病毒烟草花叶病毒(TMV)和烟草环斑病毒(TRSV)的新方法。HRP标记的羊抗兔酶标记抗体IgG-HRP可以催化H2O2氧化联苯胺的反应,其氧化产物在Briton-Robinson(BR)缓冲溶液中在-0.62V(SCE)左右产生灵敏的线性扫描二阶导数伏安峰,可以测定IgG-HRP。根据IgG-HRP与植物病毒及其抗血清的免疫反应,可以间接测定植物病毒。本法测定TMV的检出限为0.25ng/mL,线性范围为0.25~5000ng/mL;测定TRSV的检出限为1.5ng/mL,线性范围为1.5~3000ng/mL;测定TMV烟草病叶澄清液的最高稀释比为1∶10000。检测灵敏度高于酶联免疫吸附显色光度法(ELISA)  相似文献   

3.
在pH4.1醋酸盐缓冲溶液及100℃加热条件下,痕量铜(Ⅱ)对结晶紫(CV)(Ep=-0.65V)氧化次亚磷酸钠的缓慢反应有很强的催化作用,采用固定时间法借自来水冷却中止反应,拟定了测定铜的催化反应-伏安法,线性范围为3~60ng/mLCu,检出限为1ng/mLCu,方法应用于植壮素中铜的分析,获得较好结果.  相似文献   

4.
溶剂浮选光度法测定痕量铜   总被引:18,自引:3,他引:18  
提出了利用溶剂浮选富集DDTC-Cu(Ⅱ)体系测定水样中痕量铜的方法(DDTC为二乙胺二硫代甲酸钠)。质量浓度的检出限为0.05ng·mL^-1,线性范围为0.0 ̄6.0ng·mL^-1,测定含Cu(Ⅱ)4.0ng·mL^-1的样品,相对标准偏差为0.85%,已用于天然水中Cu(Ⅱ)的测定。  相似文献   

5.
设计了在线液-液萃取多用重分布相器及相应流动注射流路系统与ICP-AES法联用。具有良好的分析性能,通过对矿石中某些重稀土元素在硝酸介质中被TBP萃取的应用研究表明钇,镱,铒的检出限(3σ)分别为6.8ng/mL,0.2ng/mL和1.5ng/mL,精密度(RSD%)分别为0.24,0.47和1.8,进样频率为25-30个/h。  相似文献   

6.
在pH4.1醋酸盐缓冲溶液及100℃加热条件下,痕量铜(Ⅱ)对结晶紫(CV)(Ep=-0.65V)氧化次亚磷酸钠的缓慢反应有很强的催化作用,采用固定时间法借自来水冷却中止反应,拟定了测定铜的催化反应-伏安法,线性范围为3~60ng/mL,Cu,检出限为1ng/mL,Cu方法应用于植壮素中铜的分析,获得较好结果。  相似文献   

7.
氢化物—原子吸收光谱法测定六味地黄丸中砷和锑   总被引:2,自引:0,他引:2  
本文建立了氢化物原子吸收光谱法测定六味地黄丸中砷和锑的方法。方法的相对标准偏差砷为1.3%,锑为1.6%,回收率在90%-110%之间,检出限分别为砷0.06ng/mL,锑0.1ng/mL,本方法可用于中成药中砷和锑的测定。  相似文献   

8.
设计了在线液-液萃取多用重力分相器及相应流动注射流路系统与ICP-AES法联用,具有良好的分析性能.通过对矿石中某些重稀土元素在硝酸介质中被TBP萃取的应用研究表明钇、镱、铒的检出限(3σ)分别为:6.8ng/mL、0.2ng/mL和1.5ng/mL.精密度(RSD%)分别为0.24、0.47和1.8.进样频率为25~30个/h.  相似文献   

9.
本文提出一种测定痕量钼的微分吸附计时电位法,利用悬汞电极作为工作电极,在0.12mol/LHAc-0.01mol/L,NaAc-3.2×10^-6mol/L茜素红的最佳底液中,测定钼的线性范围为0.4ng/mL~70ng/mL,吸附富集3min检测下限可达0.1ng/mL。探讨了影响方法灵敏度的主要因素,初步研究了电极过程,利用该方法直接测定了粮食样品中钼的含量。  相似文献   

10.
导数—同步荧光光谱法同时测定三种B族维生素的研究   总被引:6,自引:0,他引:6  
研究了维生素B1的氧化产物(硫色素)、维生素B2和B6混合物体系的导数-同步荧光光度谱,提出了混合物体系荧光光谱被分辨开的同时测定方法,该法可不经分离直接测定复合维生素片剂中维生素B1,B2及B6,其线性范围均为0-1.0μg/mL,检出限分别为0.5、1.5及4.0ng/mL。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

14.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

15.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

19.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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