全膜碳纤维阳极溶出伏安法测定汞

阐述了用金膜碳纤维电极差分脉冲阳极溶出伏安法测定水中微量汞的方法,讨论了支持电解质、镀金方式和金膜厚度对溶出峰电流i_p的影响,方法的线性范围为0.5—10 ppb,检测下限为 0.5 ppb,对标准水样(SB 0901)中汞的测定,变异系数为10.5％,相对误差为 1.3％,t 检验方法可靠。     

2,3,16,17-四羧基酞菁钴对氧还原的电催化作用

用循环伏安法及旋转圆盘-环电极研究了2,3,16,17-四羧基酞菁钴(CoTCPc)在溶液中及CoTCPc/GC修饰电极上对O_2还原的电催化作用。实验结果表明,CoTCPc对O_2电还原有明显的催化作用。在Co(Ⅱ)TCPc还原为Co(Ⅰ)TCPc的第一个峰电势附近,O_2在CoTCPc/GC修饰电极上定量地还原为H_2O_2,在稍负的第二个峰电势附近,有H_2O_2还原产生H_2O的过程发生。本文并对CoTCPc对O_2还原电催化过程的机理进行了讨论。     

微分脉冲阳极溶出伏安法测定饮水中痕量镉

用F—78脉冲极谱仪,以玻碳汞膜电极为工作电极,选择0.1MNaAc—0.1MHAc—0.1MKCl作底液,对饮水中痕量镉进行阳极溶出伏安测定。研究了影响镉溶出峰电流大小的各种因素,确定了测定饮水中镉的最佳条件。对贵州大学饮水的测定结果表明:平均镉含量<1×10~(-4)μg.ml~(-1),远低于我国“地面水环境质量一级标准”的规定。(镉含量≤1ppb)     

吸附溶出伏安法同时测定水中痕量锌和镉

报道了同时测定痕量锌和镉的新方法 .在 0 .0 1mol/LHAc - 0 .0 1mol/LNaAc- 1.2× 10 - 5mol/L乙醛酸缩氨基硫脲 (GATSC)中 ,Zn -GATSC和Cd -GATSC均产生非常灵敏的吸附波 ,峰电位分别是 - 0 .82V和 - 0 .4 3V(vs·SCE) ,峰电流和锌、镉的浓度分别在 3.0× 10 - 8～ 8.0× 10 - 7mol/L和 1.0× 10 - 8～ 6 .0× 10 - 7mol/L范围内成直线关系 ,检测限分别是 8.0× 10 - 9和 3.0× 10 - 9mol/L .该方法用于测定水中痕量锌和镉 ,结果令人满意     

玻碳电极吸附循环伏安法测定植酸含量

本文阐述一个测定植酸含量的方法。测定结果与光度法相符。测定植酸中总磷和无机磷的变异系数(n=5)分别为0.66％和0.75％;回收率分别为99.7％—100.2％和99.3％—100.8％。在选定的最佳条件下,磷浓度在0.5～50ug/ml范围内与第一氧化峰电流值呈线性,检测线低于0.5ug/ml磷。     

芦丁和稀土－芦丁络合物伏安行为的研究

在乙醇量小于５％的水溶液中，于ｐＨ２．０～５．２和５．０～１０．０分别得到芦丁的两个还原波。前者为芦丁分子的吸附波，后者为其一价阴离子的还原波，均为羰基的两电子还原过程。在ｐＨ８的氨性底液中，稀土离子和芦丁形成非电活性络合物，使芦丁还原波降低。在适宜条件下，可检测１０~（－７）ｍｏｌ／Ｌ重稀土离子。测得络合物组成为ＲＥ（Ⅲ）：Ｒｕｔｉｎ＝１：２。由稀土离子与桑色素、槲皮素和芦丁三种多羟基黄酮试剂络合物的伏安行为的不同，讨论了不同配位位置对络合物伏安行为的影响。     

Fabrication and magnetic properties of Co nanowire arrays of different crystal structures

It is important to find some developing high-density magnetic recording materials in magnetic recording field with the development of information and technique, in which vertical magnetic recording is a very important way and has received considerable attention[1—3]. The vertical magnetic recording materials require high squareness, suitable coercivity, and small size of storage element[4]. Someone used nanoporous anodic aluminum oxide as templates to fabricate uniform arrays of multi magneti…     

Ultraviolet photoluminescence of porous anodic alumina films

Photoluminescence (PL) properties of porous anodic alumina (PAA) films prepared by using electrochemical anodization technique in a mixed solution of oxalic and sulfuric acid have been investigated. The PAA films have an intensive ultraviolet PL emission around 350 nm, of which a possible PL mechanism has been proposed. It was found that the incorporated oxalic ions, which could transform into PL centers and exist in the PAA films, are responsible for this ultraviolet PL emission.     

<Emphasis Type="Italic">In situ</Emphasis> generation and detection of methyl radical by voltammetry

The chemistry of free radicals is one of the advanced subjects of fundamental sciences such as biomedicine, environment protection, new energy sources and new material. The detection technique of free radicals is an essential tool for studying free radicals. Methyl radical is one of the representatives of alkyl radicals and the studies on it attract more attention. The current approaches to obtaining methyl radical are based on pulse radiolysis of organic substances that contain the methyl gro…