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1.
报道了新息夫碱试剂水杨醛缩-5-碘-8-氨基喹啉(SAIAQ)的合成。用元素分析、红外光谱法确定了其结构。测定了SAIAQ的酸度常数Ka1=2.40×10-4,Ka2=2.98×10-9。在pH3.50~5.00范围内SAIAQ与Ga3+形成稳定的荧光螯合物,且在λex/λem=428nm/540nm产生强烈荧光。其荧光强度与Ga3+的浓度在1.5μg/L~260μg/L范围内呈线性关系,检出限1.5μg/L,考察了共存离子的影响,选择性高。已应用于煤渣中痕量镓的分析。  相似文献   

2.
报道了新息夫碱试剂水杨醛缩-5-碘-5-氨基喹啉(SAIAQ)的合成。用元素分析、红外光谱法确定了其结构。测定了SAIAQ的酸度常数Ka1=2.40×10^-4,Ka2=2.98×10^-9。在pH3.50 ̄5.00范围内SAIAQ与Ga^3+形成稳定的荧光螯合物,且在λex/λem=428nm/540nm产生强烈荧光。其荧光强度与Ga^3+的浓度在1.5μg/L ̄260μg/L范围内呈线性关系,  相似文献   

3.
本文利用鲁米诺-KIO4-Fe(1,10—phen)32+配合物体系产生化学发光反应,建立了测定痕量铁的新的化学发光分析方法。该法以1,10-phen为配位体,铁的检出限为1.6×10-7g/L,工作曲线响应浓度范围在1×10-5-1×10-3g/L。在测定2×10-4g/L铁的相对标准偏差为3.5%。用于检测工业沉淀BaSO4中痕量铁获得满意结果。  相似文献   

4.
缝管原子捕集方法研究   总被引:1,自引:0,他引:1  
试验了各种条件对Bi、Ga、Sb灵敏度影响。结果表明,分别用不同的火焰条件进行原子捕杀与放可获得最佳灵敏度。捕集1min,测得Bi、Ga、Sb的特征浓度依次为3.5×10-3、1.6×10-3、1.8×10-3μg·ml-1,它比常规火焰原子吸收光谱法的灵敏度分别提高254、131、239倍。Bi、Ga、Sb的变异系数各为2.9、3.5、4.7%。本法测定了纯锡中微量Bi、Sb。  相似文献   

5.
本文对用于原子吸收光谱分析的在线液-液萃取流路系统进行了研究,采用了一种新型、适用、简便的相分隔器和相分离器,并用该流路系统对矿石、人发中的Cu(FAAS)以及矿石中痕量Au进行了测定(GFAAS)。在水相和有机相的流量比为25:1,采样频率为20h ̄(-1)时,用FAAS法测定Cu的RSD为1.9%(n=10)、DL(3σ)为1.0μg.L ̄(-1);用GFAAS法测定Au的RSD为4.9%,n=10、DL(3σ)为0.08μg.L ̄(-1) 。  相似文献   

6.
SYNTHESIS OF 2,3-DEHYDRO-4,9β-DIHYDROXY-β-DIHYDROAGAROFURANFaJunNAN;ZhaoMingXIONG;LiJunLIU;TongShangLI;YuLinLI(StateKeyLabora...  相似文献   

7.
采用流动注射法研究了巯基化合物-铈(Ⅳ)-氢化可的松(HCRs)体系的化学发光行 为,对影响化学发光强度的诸因素进行试验和探讨,建立了流动注射化学发光法检测谷胱甘 肽(GSH),半胱氨酸(Cys)等含巯基化合物的新方法。检测GSH和Cys和线性范围分别为 2.0×10-6~10.0×10-5mol/L和1.0×10-6mol/L~10.0×10-5mol/L;检测限分别为2.0 ×10-7mol/L和1.4×10-6mol/L(S/N=3);GSH、Cys加入血清中进行回收测定的回收率 为90%~95%,相对标准偏差小于4%。  相似文献   

8.
本对用于原子吸收光谱分析的在线液-液萃取流路系统进行了研究,采用了一种新型、适用、简便的相分隔器和相分离器,并用该流路系统对矿石、人发中的Cu(FAAS)以及矿石中痕量Au进行了测定(GFAAS)。在水相和有机相的流量比为25:1,采样频率为20h^-1时,用FAAS法测定Cu的RSD为1.9%(n=10)、DL(3σ)为1.0μg·L^-1;用GFAAS法测定Au的RSD为4.9%,n=10、  相似文献   

9.
侯列奇  王树安 《分析化学》1995,23(8):919-921
本法对U3Si中22个微量杂质元素的测定,进行了较系统的实验研究,取样100mg时,Al、Ca、Cd、Cr、Cu、Fe、Hf、In、Mg、Mn、Mo、Nb、Ni、Pb、Sn、Ta、Ti、V、Y、Zn和Zr的测定范围5μg/g-800μg/g,回收率为94%-105%,RSD(n=8)0.4%-1.2%。  相似文献   

10.
离子色谱法测定α—氧化铝中微量硫酸根的研究   总被引:1,自引:0,他引:1  
吴介达  吕伟 《分析化学》1994,22(2):172-174
本建立了用氢氧化钠溶样,离子色谱测定α-Al2O3中微量硫酸根的方法。在DionexAS4A分离柱上,用1.8×10^-^3mol/LAa2CO3作流动相进行洗脱,电导检测器检测,分析方法简便,快速,硫酸根的检测限为1.0×10^-^2μg/ml,相对标准偏差为2.67%,回收率为97.5%,扩展了离子色谱法测定实际样品的范围。  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.
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   

13.
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   

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.
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   

19.
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   

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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