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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
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2.5次微分溶出伏安法测定茶叶中痕量锌 总被引:4,自引:0,他引:4
本报告了测定痕量锌的一种新方法,在0.01mol/LHAc-0.01mol/LNaAc溶液中,锌和乙醛酸缩氨基硫脲形成的配合物产生一个很灵敏的还原峰,峰电位是一-0.82V(vs.SCE),锌的浓度在2.0×10^-8-8.0×10^-7mol/L范围内与峰高呈直线关系,检测限是6.0×10^-9mol/L,该方法用于测定茶叶中痕量锌,结果令人满意。 相似文献
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铜—腺嘌呤络合物吸附波的研究 总被引:1,自引:0,他引:1
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
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在pH4.2的HCl-NaAc缓冲溶液中,Sn(Ⅳ)-β-巯基丙酸(MPA)络合物产生一灵敏的极谱吸附波,峰电位在-0.60V(vs.SCE),峰高与Sn浓度在4.2×10-9~3.4×10-6mol/L范围内呈线性关系,检出限为2.0×10-9mol/L。本文对极谱波的性质和电极反应机理进行了研究。本法用于罐头食品中痕量锡的测定,结果满意。 相似文献
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镓—茜素紫极谱络合吸附波的研究 总被引:3,自引:0,他引:3
在含有0.05mol/L HAc-NaAc(pH5.6)、0.1mol/L KCL和1.5×10^-5mol/L茜素紫的溶液中,镓(Ⅲ)-茜素紫络合物在单扫示波极谱仪上产生一灵敏的导数极谱波,峰电位在-1.11V(vs.SCE),峰电流与镓(Ⅲ)浓度在2.0×10^-8mol/L。机理研究表明,峰电流是由吸附在电极表面的络合物中的中心离子和配位体同时还原而产生的。方法已应用于铝合金中镓的测定,结果 相似文献
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在pH4.0的HAc-NaAc缓冲介质中,Sn(Ⅱ)与1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5(PMBP)生成络合物,于-0.74V(vs.SCE)出现一灵敏的极谱峰。锡含量在4.2×10-8mol/L~3.4×10-6mol/L范围内与峰高呈线性关系,检出限为1.7×10-8mol/L。用多种电化学方法研究了极谱波的性质及电极反应机理,证明该极谱波为络合吸附波,峰电流由中心离子Sn(Ⅱ)还原产生,络合物组成为Sn(Ⅱ)∶PMBP=1∶1。试验了多种离子对峰电流的影响。方法已用于矿样中痕量锡的测定。 相似文献
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在含有0.05mol/LHAc-NaAc(pH5.6)、0.1mol/LKCl和1.5×10 ̄(-5)mol/L茜素紫的溶液中,镓(Ⅲ)-茜素紫络合物在单扫示波极谱仪上产生一灵敏的导致极谱波,峰电位在-1.11V(vs.SCE),峰电流与镓(Ⅲ)浓度在2.0×10 ̄(-8)~2.0×10 ̄(-6)mol/L范围内呈线性关系,检测限达1×10 ̄(-8)moL/L机理研究表明,峰电流是由吸附在电极表面的络合物中的中心离子和配位体同时还原而产生的。方法已应用于铝合金中镓的测定,结果满意。 相似文献
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亚硝酸根—巯基乙酸—钴(Ⅱ)络合物的极谱吸附波研究 总被引:7,自引:0,他引:7
提出了一个测定痕量亚硝酸根的极谱吸附波新体系.在含有巯基乙酸(TGA)和钻.(Ⅱ)的 pH 4.4的 H2SO4-NaAc介质中,得到一灵敏的亚硝酸根络合物单扫极谱吸附波,峰电位为-0.75 V(vs.SCE).峰电位与亚硝酸根浓度在1.1× 10-3-8.7×10-6mol/L范围内呈线性关系.检出限为 5. 5×10-9 mol/L.本法简便快速,选择性好,用于水样和食品中痕量NO-2的测定,结果满意。 相似文献
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利用手持技术改进测定乙醇分子结构实验 总被引:1,自引:0,他引:1
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。 相似文献
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Mustafa R. Ibrahim Zacharia A. Fataftah Paul von Ragu Schleyer Peter D. Stout 《Journal of computational chemistry》1987,8(8):1131-1138
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases. 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1989,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988. 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1988,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae. 相似文献
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由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。 相似文献
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