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1.
安力农的极谱测定及其电化学行为   总被引:4,自引:0,他引:4  
张成志  徐变珍 《分析化学》1997,25(10):1185-1188
在pH5.6,0.15mol/L磷酸盐缓冲溶液(PBS)中,得到了安力农的灵敏极谱吸附波,波的二阶导波高在2×10^-8~8×10^-6mol/L范围内与安力农的浓度成直线关系,检测下限为1×10^-8mol/L,测定出电极过程的电子传递系数a=0.43,表面电极反尖速率常数ks=3.3s^-1,安力农在汞电极上的吸附遵从Langmuir等温式,测得其吸附系数β=8.1×10^5。  相似文献   

2.
钙—芦丁极谱络合吸附波的研究   总被引:3,自引:0,他引:3  
在0.01mol/LKOH底液中,用单扫示波极谱法可获得钙-芦丁络合吸附波,检出限为8.0*10^-7mol/L.电极表面反应速率常数为ks=d1.27s^-1。  相似文献   

3.
锗—芦丁极谱络合吸附波的研究   总被引:8,自引:0,他引:8  
在醋酸盐缓冲底液中,可获得Ge-芦丁的2个灵敏的络合吸附波P1和P2,分别对应于络合物中Ge(Ⅳ)还原至Ge(Ⅱ)再还原至Ge(0)。两波的检出限分别为8.0×10^-8和4.0×10^-8mol/L。测得电活性络合物的组成为Ge:Rt=1:3,表面电极反应的速率常数(ks)1=10.5 s^-1,(ks)2=1.9s^-1。还测定了有机锗口服液中锗的含量。  相似文献   

4.
吗吲哚的示波极谱法研究   总被引:2,自引:0,他引:2  
鲁毅强  胡劲波 《分析化学》1998,26(3):348-350
在0.1mol/L H2SO4溶液中,吗吲哚出现一灵敏的示波极谱导数还原峰,峰电位为-0.76V(vs.SCE),峰电流与吗吲哚浓度在1.0×10^-7 ̄5.0×10^-6mol/L范围内呈线性关系;相关系数为0.9998;检出限为3.0×10^-8mol/L。用于片剂测定,得到令人满意的结果,用线性扫描和循环伏安法等手段研究了体系的吸附性和电极反应机理,测定了有关常数和参数。证明该还原波为不可逆  相似文献   

5.
甲氟哌酸的极谱伏安行为研究及其应用   总被引:3,自引:0,他引:3  
本较详细研究了甲氟哌酸的极谱伏安行为。在0.02mol/L氯化铵底液中,甲氟哌酸产生一个良好的还原峰,峰电位(Ep)为-1.450V。其导数峰高与浓度在9×10^-5-3×10^-7mol/L范围内呈现良好的线性关系,大多数金属离子和无机阴离子不干扰测定,用于甲氟哌酸合杨样品的测定,结果满意。本还用多种电化学方法和技术研究了还原峰电流的性质,并提出了电极反应的机理。  相似文献   

6.
徐斌  张海丽  邹欣平 《分析化学》2000,28(12):1519-1522
用线性扫描示波极谱法研究了镉(Ⅱ)-茜素紫-邻二氮菲体系的极谱行为,发现在含有0.1mol/L KCl、pH=2.85的HAc的溶液中,镉(Ⅱ)-茜素紫-邻二氮菲体系产生-灵敏的极谱吸附波,共峰电位为-0.64V(vs.SCE),峰电流与镉(Ⅱ)的浓度在5.0*10^-8-1.0*10^-6mol/L的范围内呈一性关系;检出限为3.0*10^-8mol/L。研究了电极反应机理,并用建立的方法成功地测定了废水样中的镉。  相似文献   

7.
舒必利的示波极谱测定与电化学行为   总被引:1,自引:0,他引:1  
曾泳淮  宋琦 《分析化学》1997,25(1):56-58
在PH5.0的HAc-NaAc底液中,舒必利在汞电有上有一灵敏的导数还原峰,峰电位为-1.78V。峰电流与舒必利的浓度在4.0×10^-7--8.0×10^-6mol/L范围内有线性关系。检测奶为1.0×10^-7mol/L。该法应用于剂中必利含量的测定,结果含人满意。还对舒必利在电极上的电化学行为特别是其吸附性进行了探讨。  相似文献   

8.
催化动力学极谱法测定痕量钯的研究   总被引:1,自引:0,他引:1  
研究了催化动力学极谱法测定痕量钯的方法,在盐酸介质中,钯催化次磷酸钠与钼酸铵反应生成磷钼蓝,用氨-氯化铵缓冲液调节溶液pH值为9.26可抑制催化反应条件,并在单扫描示波极谱仪上于-1.24V(vs.SCE)产生一灵敏极谱波,导数波高与钯0.05~1.0ng.ml^-1呈线性关系,检出限为0.03ng.ml^-1,研究了极谱波性质及机理,证明其为吸附波,方法用于合成样及电镀废液中的钯测定,结果满意。  相似文献   

9.
在HAc-NaAc(pH4.0)底液中,用单扫示波极谱法可得到一个灵敏的阿西美辛导数还原峰,峰电位为-1.22V(vs.SCE),峰电流与阿西美辛浓度在1.0*10^-7-8.0*10^-6mol/L范围内呈线性关系(r=0.9994),检出限为1.0*10^-8mol/L。该法已应用于模拟尿样和胶囊中阿西美含量的测定。  相似文献   

10.
单扫描示波极谱法测定甘草酸   总被引:3,自引:0,他引:3  
本文报道测定甘草酸的单扫描法波极谱方法,在0.1mol/LNaAc-HAc(pH4.1±0.1)缓冲液中,甘草酸还原波峰电位为-1.38V(vs.SCE),峰高与其浓度在2.0×10^-6~1.0 ×10^-4mol/L范围内有线性关系,检测限为1.2×10^-6mol/L。甘氨酸,半胱氨酸等不干扰测定。应用本方法测定强力宁注射液中甘草酸含量,结果令人满意。本文还讨论了电极过程机理。  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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