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1.
锗(Ⅳ)-邻苯二酚紫-钒(Ⅳ)体系的极谱吸附催化波研究   总被引:5,自引:0,他引:5  
在0.1mol/LH2SO4溶液中,Ge(Ⅳ)-邻苯二酚紫(PV)-V(Ⅳ)体系产生一灵敏的吸附催化波,峰电位在-0.55V(vs.SCE)处.锗浓度在2.2×10-10~2.8×10-6mol/L范围内与峰电流呈线性关系.检出限为1.1×10-10mol/L.研究了极谱波的性质.本法用于土壤中痕量锗的测定,结果满意.  相似文献   

2.
王升富  杜丹  邹其超 《分析化学》2002,30(2):178-182
制备了磷钼杂多酸-L-半胱氨酸自组装超分子膜电极(P2Mo18-L-Cys/Au)。采用水平衰减全反射(ATR-FTIR)光谱表征了膜的组成。研究了该膜电极的电化学性质,发现它在1.0 mol/L H2SO4溶液中,于0.0~0.7V(vs.SCE)间CV扫描出现两对稳定、可逆的氧化还原峰,其中峰电位分别为Em1=0.334 V,Em2=0.188V,对应着P2Mo18O_(62)~(6-)的两步2电子-2质子反应;计时库仑法计算了薄膜内的电子传递系数D为5.01 × 10~(-8)cm2·s~(-1)。该膜电极对酸性溶液中的NO_2~-有明显的电催化还原作用,初步探讨了电催化机理。用差分脉冲伏安法(DPV)测定其还原峰电流与NO_2~-的浓度在2.0 ×10~(-6)~2.0 × 10~(-4)mol/L范围内呈良好的线性关系,相关系数为0.9953,检测限5.0×10~(-7)mol/L。该电极用于模拟水样中NO_2~-的测定,结果满意。  相似文献   

3.
流动注射双安培法直接测定茶中单宁   总被引:11,自引:0,他引:11  
赵川  张君才  宋俊峰 《分析化学》2002,30(2):210-213
基于不可逆电对的流动注射双安培检测原理,建立了快速检测茶叶中单宁的新方法。使用经阳极化处理的双铂电极,通过偶合单宁在一支电极上的催化氧化和氧化铂在另一支电极上的还原两个不可逆电极过程,在外加电位差为0V时,单宁的氧化电流与其浓度在1.0 × 10~(-6)~1.0 × 10~(-4)mol/L范围内呈线性关系,检出限为6.0 × 10~(-7)mol/L(S/N=2)。连续42次测定1.0 × 10~(-5)mol/L单宁,电流值RSD=1.2%。本法比现行国家标准方法简单、快速、灵敏,分别对市售绿茶、花茶、乌龙茶、红茶中单宁含量进行测定,结果令人满意。  相似文献   

4.
在0.1mol/L H2SO4底液中,用碳糊电极吸附伏安法测定多巴酚丁胺,阳极峰电位为0.46V,峰电流与多巴酚丁胺的浓度在3.0×10^-9-1.0×10^-6mol/L范围内呈良好的线性关系。  相似文献   

5.
铜(Ⅱ)和锌(Ⅱ)分别在0.1mol/LKH2PO4-Na2HPO4缓冲溶液(pH6.5)和0.25mol/LNH4Cl溶液中,与氟哌酸形成良好的络合吸附波,峰电位分别为-0.26V和-1.28V(vs.SCE),络合比分别为1:3和1:2,峰电流与铜(Ⅱ)和锌(Ⅱ)的浓度均在4.0×10^-7~5.0×10^-6nol/L范围内呈线性关系,检测限分别为7.0×10^-8和5.0×10^-8mol  相似文献   

6.
在0.01mol/LNH.H2O-NH4Cl和3.0×10^-5mol/L安息香缩氨基硫脲体系中,钴产生一灵敏的还原波,其峰电位是-0.94V(vs.SCE),峰电流与钴的浓度在2.0×10-8-1.0×10^-6mol/L范围内成直线关系,检测限为5.0×10^-9mol/L,该法测定水中痕量钴结果令人满意。  相似文献   

7.
报道了测定痕量镉的一种新方法.在0.01mol/LHAc-0.01mol/LNaAc-1.2×10-5mol/L乙醛酸缩氨基硫脲(GATSC)体系中,Cd-GATSC产生一灵敏的吸附还原波,波的峰电位是-0.43V(vs·SCE),峰电流与镉的浓度在1.0×10-8~8.0×10-7mol/L范围内成直线关系.此法用于测定水中痕量镉,结果令人满意。  相似文献   

8.
吡哆醛的电化学行为研究   总被引:2,自引:0,他引:2  
用单扫示波极谱法,吡哆醛在0.2mol/LKCl+0.02mol/L naOH底液中,产生一良好的寺阶导数峰,EP=-1.30±0.01V(SCE),其峰高与浓度在2×10^-7-2×10^-4mol/L范围内成线性关系,检出限为1×10^-7mol/L实验证明,其电极过程为伴有微弱吸附性质的的可逆扩散过程(n=2),不在弱酸性和中性介质中时,吡哆醛的电极过程为前行动力学过程,其电极反应机理为伴有  相似文献   

9.
杨运发  时莉 《分析化学》2000,28(8):974-977
用线性扫描伏安法(ISV)、微分脉冲伏安法(DPV)和循环伏安法(CV)在玻碳电极 (GCE)上研究了麦地霉素(MD)在不同介质中的阳极伏安行为。发现在0.1mol/L Na_2HPO_4溶 液中于0.75V(υs. Ag/AgCl)左右产生一个阳极氧化峰,峰高与MD浓度5 × 10~(-5)~1×10~-1g/L 范围内呈线性关系。用本法不需分离直接测定了药物制剂和加标尿样。RSD为1.8%(n= 10)。尿样中MD的回收率为95%~115%。实验结果表明MD的电极氧化反应为不可逆过 程。  相似文献   

10.
铜—腺嘌呤络合物吸附波的研究   总被引:1,自引:0,他引:1  
田诚  王宏 《分析科学学报》1997,13(2):133-135
了在0.08mol/LNaAc~0.02mol/LHAc缓冲溶液铜与腺嘌呤(Ade)络合物的极谱行为,结果表明,扫描电压为-0.2V~-0.7V时铜-腺嘌呤络合物在单扫示波极谱上有一络合物吸附波,其一阶导数峰电位主-0.4V(vs.SCE),腺嘌呤浓度在1.0×10^-6~1.0×10^-5mol/L范围内与一阶导数波高呈良好的线性关系,检出限为1.0×10^-7mol/L,实验证明,该峰具有吸附  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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