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1.
《Analytical letters》2012,45(8):739-745
Abstract

A method for the determination of metronidazole in pharmaceutical tablets is presented. Differential pulse polarography at a static mercury drop electrode is used to observe the reduction of the imidazole. The method is demonstrated to be simple, rapid, linear, reproducible and accurate.  相似文献   

2.
微分脉冲极谱同时测定三种碱性氨基酸的研究   总被引:4,自引:1,他引:4  
应用微分脉冲极谱,在pH9.0 NaB4O7- CH3CHO-Co2+- NaOH组成的极谱底液,扫描电位- 0.80~- 1.60 V、振幅 20mV、扫描速度5mV/s、一滴汞周期2s的条件下进行连续扫描测量三种碱性氨基酸,获得三个灵敏 度和分辨率均较高的极谱峰图。该法简便快速,稳定可靠,为测量各种蛋白质中的三种磁性氨基酸提供一种新途 径。  相似文献   

3.
《Analytical letters》2012,45(20):2301-2308
Abstract

The overall formation constants of the Cd (Trimethylene-diamine) system were determined by differential pulse polarography at 25°C and at μ = 1 (NaNO3). The percentage distribution of cadmium present in various forms as a function of ligand concentration was calculated.  相似文献   

4.
A new differential pulse polarographic (DPP) method has been developed for the trace determination of boron. Its most stable copper complex is used in 0.5 M KNO3 electrolyte since boron is not electroactive. By continuous addition of tetraborate to copper solution, the copper peak decreased first but then the peak became very small and nearly constant. This point was used for the boron determination. It was found that one mole of copper used two moles of tetraborate. Using this relationship, 1×10?5 M tetraborate could be determined. The quantification limit was 2.5×10?6 M and detection limit was 8×10?7 M. In the presence of complex forming ions such as Pb, Zn, and Cd, the borate found in sample was somewhat smaller because of their reaction with borate. But since their complexes were not as strong as copper, only a few percent of borate were used. No interference was observed in the presence of calcium, chloride and sulfate. This method is applied for the determination of B in borax ore, waste water of borax industries and tap water of Ankara city.  相似文献   

5.
《Analytical letters》2012,45(15-16):1633-1651
Abstract

A method is described for the simultaneous determination of nickel and cobalt in manganese sulphate electrolyte by the dimethylglyoxime (DMGH2) sensitized differential pulse polarography. The high manganese sulphate background (1.2M) in the concentrated process plant electrolyte interferes only with the nickel determination and precludes its direct determination. A 50% v/v dilution and an excessive amount (2 × 10?3M) of the chelating agent are required at pH7.7 for the reliable determination of both elements. Under these conditions, the linear concentration ranges are 0-110 μg/1 for nickel and 0-140 μg/1 for cobalt. The minimum detectable amounts above the levels present in the process plant electrolyte are 2 μg/1 and 1 μg/1 for both elements, respectively. The relative standard deviations for all measurements are between 1 and 3%.  相似文献   

6.
《Analytical letters》2012,45(12):2055-2063
Abstract

Differential pulse(d. p.)polarography has been used to study the simple and mixed ligand complexes of 1, 3 diaminopropane (DAMP) and phthalate(PHLT) with Cd(II) at constant ionic strength (u= 1.0 M NaNO3) at 25°C The overall formation constants of simple and mixed complexes were calculated. The reduction of the simple and mixed species is reversible and diffusion controlled. The postive values of the mixing constants for the mixed-ligand complexes indicate that the mixed-ligand complexes are more stable than simple binary complexes. The equilibria between the various mixed-ligand species in the solution and their equilibrium are given.  相似文献   

7.
《Analytical letters》2012,45(8):1505-1518
Abstract

A simple and rapid differential pulse polarographic assay for measurement of platinum drug binding to DNA is described. The method makes it possible to determine the free (unbound) platinum compound in the presence of DNA or platinum - DNA complex. The method is based on the polarographic catalytic hydrogen current yielded by platinum (II) or (IV) complexes in formaldehyde - hydrazine - sulphuric acid background electrolyte, in which DNA or platinum - DNA complex precipitate. The lower level of analytical utility of this method is c. 1 × 10?9 M.  相似文献   

8.
《Analytical letters》2012,45(9):793-804
Abstract

A rapid, reproducible and accurate method for the determination of benzoylmetronidazole in pharmaceutical suspensions is presented. Differential pulse polarography at a static mercury drop electrode is used for the reduction of the nitro group of benzoylmetronidazole.  相似文献   

9.
极谱法测定地质样品中痕量氯   总被引:7,自引:2,他引:7  
提出了0.1%HCOOH-8×10^3%百时香酚兰,-0.4mol/LHClO4-0.4%TritonX-100极谱法痕量氯离子的新体系,检出限为0.18μg/g,RSD为7.6%,标准样品测定结果与推荐值相吻合。  相似文献   

10.
《Analytical letters》2012,45(5-6):587-596
Abstract

The method proposed for determining codeine, dionin and thebaine by differential pulse polarography is based on the reduction (in ammoniacal medium) of the nitroderivatives obtained by dissolving the substances in concentrated nitric acid. The values of the reduction potentials range between -0.45 and -0.69 V. Morphine and heroine do not interfere in the determination of the mentioned alkaloids.  相似文献   

11.
一阶导数差示脉冲极谱法用于扑热息痛的定量分析   总被引:2,自引:1,他引:2  
梁云爱  孙金辉 《分析化学》1994,22(4):359-362
一阶导数差示脉冲极谱法用于扑热息痛及其制剂的定量分析,在乙醇-水-2.0×10^-^3mol/LH2SO4(12.5:11.5:1)的溶液中,于0.24V(usAg/AgCl)处出现良好的一阶导数差示脉冲极谱峰,在3.3×10^-^4~3.3×10^-^3mol/L范围内,浓度与其一阶导数差示脉冲极谱峰值呈线性关系,检测限为7.8×10^-^8mol/L。方法简便,快速,灵敏,结果准确。  相似文献   

12.
单扫示波极谱法测定痕量亚硝酸根   总被引:6,自引:0,他引:6  
在前文的基础上,经进一步研究发现,在Co~(3+)-SCN~--抗坏血酸介质中(pH=2),也可得到灵敏的亚硝酸根的极谱还原波,并对该波的机理进行了初步的研究。 1 实验部分 1。1 仪器和试剂 JP-2型示波极谱仪(成都仪器厂),三电极系统;PAR-370电化学系统(美国PAR公司),M303型静汞滴电极(SMDE);501型超级恒温水浴(25±0.2℃)。高纯二氧化碳除氧。  相似文献   

13.
14.
定量测定秦皮中秦皮甲素的二阶导数示差脉冲极谱法   总被引:3,自引:0,他引:3  
建立了中草药秦皮中秦皮甲素的二阶导数示差脉冲极谱定量分析方法。秦皮甲素在乙醇-2mol/L氯化锂-水(体积比2:1:5)的底液中,于-1.703V(vs Ag/AgCl)处出现一良好的二阶导数示差脉冲极谱峰,其峰幅值与秦皮甲素在0.2-1.6mmol/L范围内呈非常显著的线性关系(P<0.01),检测下限脒50mmol/L。该法简便、快速、灵敏,结果准确。  相似文献   

15.
Abstract

A differential pulse polarographic method has been developed for the simultaneous low level determination of nickel and cobalt in the presence of furildioxime in natural waters. The nature of the electrode processes was studied with cyclic voltammetry. Limits of determination of 0.4 μg/L and 0.15 μg/L were achieved for nickel and cobalt respectively  相似文献   

16.
《Analytical letters》2012,45(12):2065-2072
Abstract

A differential pulse polarographic study of the complexation of cadmium(II) with imidazole gives the relationship, Ej/2 = -0.798 – 0.132 log [imidazole]t for the cadmium(II) half wave potential (E]/2) with imidazole concentration. Also, the differences between the half-wave potentials (ΔEj/2) of the complex and metal ion have been used to determine log gn (6.75) and coordination number (4) for the cadmium-imidazole complex according to Subrahmanya's method.  相似文献   

17.
《Analytical letters》2012,45(20):2581-2589
Abstract

The anodic oxidation of melphalan was studied on a glassy carbon disk electrode, either stationary or rotated, using a d.c. and a differential pulse potential program. The conditions have been found for a differential pulse voltammetric determination of the substance, with a detection limit of 1 × 10?6 mol 1?1  相似文献   

18.
叶酸的示差脉冲极谱研究   总被引:1,自引:0,他引:1  
  相似文献   

19.
提出了草酸的微分脉冲极谱测定方法.草酸在0.05 mol·L-1邻苯二甲酸氢钾-1.0 mol·L-1硫酸锂底液中,扫描范围为-1.80~-1.20 V(vs.Ag/AgCl)时,分别在-1.29 V(EP1),-1.54 V(EP2)和-1.76 V(EP3)电位处出现3个微分脉冲极谱峰,由于EP3处存在杂质峰干扰,且EP2与EP3两峰无法完全分离,试验选择-1.29 V(EP1)处的微分脉冲极谱峰作为草酸定量分析的测定峰.对乙醛酸共存时乙酸的测定方法经行了论证.草酸浓度与其极谱峰峰电流呈线性关系,线性回归方程y=-24.080 6+37.344 3x,相关系数为0.997 9.方法用于9.018 g·L-1草酸标准溶液的测定,相对标准偏差(n=5)为0.23%,加标回收率在99.6%~100.3%之间.  相似文献   

20.
《Analytical letters》2012,45(3-4):453-459
Abstract

A simple d.c. polarographic method has been developed for the determination of metronidazole in dosages forms. In Robinson - Britton buffer (pH 4.38) and in presence of 1.60 × 10?3 % Triton X-100, the drug produced a well defined 4-electron polarographic wave followed by another wave of about half the height of the first wave. The current is proportional to the concentration and permits the drug to be determined by d.c. polarography in the concentration range 5.0 × 10?5 -7.0 × 10?4 M. Results obtained by the proposed method are in excellent agreement with that provided by the USP-XX method. A rapid, sensitive and accurate polarographic method for the determination of metronidazole in the tablets which are produced locally is proposed.  相似文献   

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