共查询到19条相似文献,搜索用时 78 毫秒
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离子选择电极测定环境样品中铅 总被引:2,自引:0,他引:2
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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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
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
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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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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
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《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
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《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
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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
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《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
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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