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1.
离子选择电极测定环境样品中铅   总被引:2,自引:0,他引:2  
李宗澧  刘静 《分析化学》1993,21(1):122-122
1 引言 铅的测定多用原子吸收分光光度法和双疏腙比色法,这两种方法虽灵敏度高,但前者仪器昂贵,后者重现性差、操作繁琐、试剂不稳定、毒性大。我们用铅离子选择电极测定了几个环境样品中的铅,方法简便快速,结果与原子吸收分光光度法相符。  相似文献   

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铅离子选择电极在配体过量的条件下对游离铅离子的响应灵敏度很高,应用这种电极已测定了铅-氟配合物的各级稳定常数,本文继续研究了铅电极测定铅-氯,铅-溴配合物稳定常数的方法并在数据处理上将经典的逐级外推法与徐光宪的对数作图法结合起来提高了测定各级稳定常数的可靠性。  相似文献   

4.
新型杯芳烃为载体的铅离子选择电极   总被引:2,自引:0,他引:2  
刘育 《分析化学》2001,29(10):1121-1124
报道了5,11,17,23-四(1,1-二甲基乙基)-25,27-二羟基-26,28-二[(2-丙酰胺)乙氧基]杯[4]芳烃1的合成及以此化合物为载体研制了PVC膜铅离子选择电极。研究了不同极性的膜增塑剂和亲脂性阴离子位点对铅离子选择电极响应性能的影响,测定了铅离子选择电极的性能。铅离子选择电极对铅离子表现出优良的能斯特响应和高选择性,能在pH4.0-6.5的范围内使用,该电极可作为电位滴定的指示电极。  相似文献   

5.
本文系统地综述高性能铅离子选择电极中掺杂于膜内的含氮有机物铅离子传感载体,如双席夫碱、吡啶酰胺、酰羟胺、苯腙,以及载体分子结构特征与铅离子电极性能之间的关系。电极对铅离子的选择性能与载体分子结构密切相关,无论是在载体还是在膜基体中引入氰基都可以明显改善铅离子电极探测下限;加强传感机理的深入研究,为高性能载体的研究指明方向。  相似文献   

6.
用交流阻抗法研究了两种液膜胆R汁酸电极和两种聚氯乙烯(PVC)膜钙离子选择电极. 从体电阻R_b和电荷传递电阻R_(ct)得到膜内离子迁移活化能E_a, 及电极的表观标准交换电流密度i°_0等信息. 结果表明: E_a比R_b更能反映离子在膜内迁移的情况, 离子在PVC膜中的迁移比在液膜中困难得多; i°_0能在一定程度上反映电极性能的优劣等。  相似文献   

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镉离子选择电极电位滴定测定钙镁   总被引:2,自引:0,他引:2  
建立了以镉离子选择电极极作指示电极EDTA、EGTA电位滴定测定钙、镁的方法,详细考察了电位滴定的适宜条件,干扰离子的影响及消除办法。在四硼酸钠-氢氧化钠缓冲介质中,EGTA滴定钙,EDTA滴定钙镁含量,测定矿泉水及硅酸盐样品中钙镁含量,结果符合要求。  相似文献   

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离子选择性电极直接电位法测水硬度   总被引:2,自引:0,他引:2  
胡忠民  胡伟栋 《分析化学》1991,19(12):1460-1460
  相似文献   

11.
Bis-Schiff base, pyridyl carboxamide, acylhydroxylamine, and phenylhydrazone, acting as sensing agents in ionophore-doped membranes of lead-ion selective electrodes with excellent response characteristics, are systematically summarized according to the latest literatures and our latest researches. The relationship between the response characteristics of the lead (II) ion-selective electrode assembled by the carriers and their molecular structures is also elaborated. It is noteworthy that the selectivity of the electrode towards lead ions over other cations is closely related to the molecular structure of the carrier. The presence of cyano group would largely improve the lower detection limit whether it is introduced into the carrier or membrane matrix. The sensing mechanism should be emphasized in order to find out the direction for developing high performance carriers.  相似文献   

12.
《Analytical letters》2012,45(18):1449-1456
Abstract

Differential pulse polarography was utilized in voltammetric immunoassay to determine human albumin and albumin antiserum. Albumin was labelled with lead, which exhibited a reduction peak with E1/2 at ?680 mV vs SCE. The current is proportional to the concentration of lead labelled albumin, and hence the albumin at a fixed lead concentration, and it decreases in proportion to the amount of albumin antiserum added. Albumin concentrations of 2.0 × 10?6–10 × 10?6 M and 10–50 μl of goat albumin antiserum (titer 1:16 = maximum dilution causing precipitation with equal volume of 1 mg/ml human albumin) were measured in the presence of 2 × 10?6 M lead.  相似文献   

13.
采用反相流动注射分析方法,研究了异硫氰酸荧光素(FITC)-人血清白蛋白(HSA)标记物的化学发光性能和反应的最佳条件,建立了化学发光测定人血清白蛋白的新方法。体系的化学发光强度与人血清白蛋白的含量在0.08-16μg/mL内呈线性关系,方法的检出限为0.04μg/mL。讨论了蛋白质标记物化学发光性增强的原因。  相似文献   

14.
《Analytical letters》2012,45(10):509-514
Abstract

A solid membrane copper ion selective electrode was used for the determination of NTA via complexometric titration with copper(II). Interferences, of the type commonly found in detergents, were investigated.  相似文献   

15.
冠醚载体离子电极的选择特性研究   总被引:1,自引:0,他引:1  
阴离子选择电极选择性系数随干扰离子r_j/z_j的变化规律已有报道,但冠醚为中性载体的金属离子电极的选择性系数规律未见报道。本文采用不同桥间结构的11种苯并双冠醚作为中性载体,从钾电极出发探讨了不同冠醚电极选择性系数与干扰离子r_j/z_j间的关系;并以4种烃型双冠醚为中性载体,分别考察了它们对Li~+、Rb~+、Cs~+、Ag~+、Ba~(2+)离子的响应规律。 1 实验部分  相似文献   

16.
用铍试剂测定人血清白蛋白的分光光度法   总被引:3,自引:1,他引:3  
在pH3.6的缓冲溶液中,铍试剂Ⅲ与人血清白蛋白(HSA)能形成复合物,吸光度与HSA的含量呈线性关系;复合物的最大吸收峰波长λmax=460nm,比铍试剂本身紫移80nm左右;HSA标准曲线线性范围为20-140mg/L;实验表明该反应选择性、重复性很好,操作简便,适用测定含量范围宽,测定结果与传统的考马斯亮蓝法结果相吻合。  相似文献   

17.
《Analytical letters》2012,45(9):715-734
Abstract

The conditions for the determination of sodium thiophosphate and sodium S-(2-amino-ethyl)-thiophos-phate in the presence of phosphate ion using ion-selective membrane electrodes are described. Both thiophosphates (inorganic and organic) are hydrolyzed in acidic medium. The phosphate ion is determined with Pb(II) using a Pb2+ – selective membrane electrode.

Cysteamine is determined by potentiometric titration with Hg(I1) using a Ag+/S2? – crystal membrane electrode or by direct potentiometry with a Cu2+ selective membrane electrode. The results were verified by the iodination method.  相似文献   

18.
用荧光光谱、同步荧光光谱研究了苯胺蓝和人血清白蛋白的相互作用。研究表明,苯胺蓝对人血清白蛋白的荧光发射有明显的猝灭作用,根据不同温度下的猝灭数据,由Stern-Volmer方程推断苯胺蓝对人血清白蛋白的猝灭属于静态猝灭。计算得到了结合常数KA、结合位点数n,同时计算得到的热力学常数表明苯胺蓝和人血清白蛋白作用力类型为静电作用和疏水作用结合。同时用同步荧光光谱探讨了苯胺蓝对人血清白蛋白构象的影响。  相似文献   

19.
High concentration glucose in diabetes mellitus may stimulate nonenzymatic glycation of proteins. Hemoglobin (Hb) and human serum albumin (HSA) are among the most sensitive proteins for the modification by glucose. In this paper, we report our study of Hb and HSA modification by glucose using electrochemical methods. Compared with native Hb, it is found that highly glycated Hb presents lower electron transfer reactivity and electrocatalytic activity toward O2 and H2O2, and the glycation is glucose concentration and time dependent. Meanwhile, the changes of the electrochemical signal of heme after binding with HSA and glycated HSA have also suggested that proteins modified by high concentration glucose lasting for months and years in diabetes mellitus might be the reason for diabetes mellitus complication.  相似文献   

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