吡哌酸离子选择性电极的研制和应用

本文研究了以PPA-TBP为电活性物质的PVC膜吡哌酸离子选择性电极的制备方法.在HAc-NaAc(pH=3.7)底液中,电极响应的线性范围1.0×10-3～1.0×10-5mol/L,检测限为5.0×10-6mol/L,级差为28mV/pc.并用该电极测定了吡哌酸片剂中吡哌酸的含量,结果满意.     

地尔硫选择性电极的研制和应用

介绍以四苯硼酸-地尔硫(艹卓)离子缔合物作活性材料,研制了四种不同类型的地尔硫(艹卓)电极:普通PVC膜型.铂丝涂(PVC)膜型,碳棒涂(PVC)膜型和铂丝涂双层聚合物膜型.比较了它们的性能.通过电化学聚合,在铂丝表面先修饰一层聚苯胺薄膜,继涂含活性材料的PVC膜所制成的双膜电极.性能优于其他三种.稳定性为连续测定8小时.电位变化约为0.3mV/h,双膜电极线性范围为1.0×10~(-2)～3.8×10~(-2)mol/L.平均斜率为58.2mV/pC,检测下限为1.2×10~(-6)mol/L,在pH2.5～7.0范围内适用。电极抗干扰能力强,响应快,重现性好.     

纳米硫化镉离子敏感材料的研制及其在离子选择电极上的应用

采用均相沉淀法研制了硫化镉纳米粒子 ,对影响纳米硫化镉晶体形成的各种因素作了详细探讨 ,确定了合成纳米硫化镉的最佳工艺路线。在反应温度为 1～ 10℃ ,络合剂EDTA与镉离子的浓度比为 1.5、Cd2 的初始浓度为 0 .0 10mol·L-1、pH为 2 .0～ 2 .5、Na2 S溶液的滴加速度为 5mL/min、乙醇∶水为 1∶1的条件下 ,可得到粒径为 6 0～ 70的硫化镉颗粒。利用纳米硫化镉作为活性物质 ,研制了纳米硫化镉PVC膜电极 ,电极在镉离子浓度 1.0× 10 -1～ 1.0× 10 -5mol·L-1范围内呈线性响应 ,电极的检测下限为 3.0× 10 -6mol·L-1。K 、Na 、Ca2 、Mg2 、Cu2 、Fe2 、Co2 、Fe3 、Al3 对电极无干扰 ,但Ag 、Pb2 、Hg2 、Mn2 、Zn2 对电极有一定的干扰。     

巯基丁二酸镍(Ⅱ)自组装单分子层修饰金电极的制备及H2O2传感器的研制

制备了巯基丁二酸镍(Ⅱ)(NiL-SH)自组装单分子层修饰金电极,制做了测定H2O2 的电流型生物传感器.NiL-SH在电极表面有一个不可逆的还原峰,传感器对H2O2的还原具有快速电催化响应(＜10s).采用电子扫描电镜(SEM)对电极表面进行了表征,探讨了电极的电化学反应性质.研究了各种因素,如pH、工作电位等,对传感器响应电流的影响.用循环伏安法测定H2O2,线性范围为5.0×10-6～3.0×10-3mol /L (R = 0.999),检出限为2.0×10-6mol/L.该电极具有模拟酶特性,米氏常数KappM＝2.78mmol/L.实验表明,传感器的稳定性、灵敏度和选择性都比较好,可以用于现场测定.     

Ce^4＋／Ce^3＋缓冲溶液流动注射电势检测法测定维生素C

以Ce4+/Ce3+氧化还原体系作缓冲溶液,用流动注射电势检测法测定了维生素C,将样品注射于以0.1mol/L K2SO4作支持电解质的Ce4+/Ce3+缓冲溶液试剂流, 以流通型氧化还原电势检测电极检测维生素C与Ce4+反应引起的氧化还原电对的电势变化,对3.0×10-4mol/L Ce4+/3.0×10-4mol/L Ce3+缓冲溶液,测定维生素C的线性范围为1.0×10-4～6.0×10-4mol/L,检出限为1.3×10-5mol/L,相对标准偏差为0.36%(n=4),分析频率为120次/小时.     

Ce~(4+)/Ce~(3+)缓冲溶液流动注射电势检测法测定维生素C

以Ce4+ /Ce3 + 氧化还原体系作缓冲溶液 ,用流动注射电势检测法测定了维生素C ,将样品注射于以 0 .1mol/LK2 SO4作支持电解质的Ce4+ /Ce3 + 缓冲溶液试剂流 ,以流通型氧化还原电势检测电极检测维生素C与Ce4+ 反应引起的氧化还原电对的电势变化 ,对 3.0× 10 -4mol/LCe4+ / 3.0× 10 -4mol/LCe3 + 缓冲溶液 ,测定维生素C的线性范围为 1.0× 10 -4～ 6 .0× 10 -4mol/L ,检出限为 1.3× 10 -5mol/L ,相对标准偏差为 0 .36 % (n =4 ) ,分析频率为 12 0次 /小时。     

尿酸在纳米金-聚番红花红修饰电极上的电化学行为及修饰电极的应用研究

本研究制备了纳米金-聚番红花红复合膜修饰的玻碳电极,并利用差分脉冲法(DPV)研究了尿酸在此修饰电极上的电化学行为.结果表明纳米金-聚番红花红复合膜对于尿酸的氧化能够起到明显的电催化作用.在优化条件下,尿酸的氧化峰电流与其浓度在1.0 x 10-6～1.0×10-4mol/L范围内呈良好的线性关系,检出限为6.0×10-7 mol/L.该方法快速,准确,将聚纳米金-番红花红复合膜修饰电极用于体液中尿酸的测定,回收率在95.0 ％～100％之间.     

电容耦合非接触电导检测器的研制

利用电容耦合的原理,将环形电极直接包在石英毛细管外壁,研制成一种电容耦合非接触电导检测(C4D).采用毛细管电泳技术评价了该检测器,对碱金属、碱土金属的浓度检测限为5×10-7～5×10-6mol/L,响应值在10-6～10-3mol/L的线性相关系数R＞0.999.该检测器结构简单,彻底克服了电化学检测器电极易污染的缺点.     

铋酸盐－依诺沙星修饰碳糊电极的制作及应用

以依诺沙星与硝酸铋(配合比11)的缔合物作为电活性物质 ,研制了铋酸盐 -依诺沙星修饰碳糊电极。该电极对溶液中依诺沙星有良好的线性响应响 ,响应斜率为56.7mV/pC,线性范围达4个数量级 ,检出限为1.0×10 -5mol/L。十几种常见无机离子与一些吡啶类离子对电极基本无干扰。该电极可用直接电位法测定市售药片中依诺沙星的含量 ,RSD<0.5 % ,回收率在99.8 %～100.3 %之间。     

镍球铂基氮气镀汞膜电极研制及性能测试

本文研制了镍球铂基氮气镀汞膜电极,并采用2.5次微分新极谱法对电极性能进行考查,镉在0.1MKCI 中线性范围1×10~8～6×10-11M,电极性能稳定、灵敏度高、重现性好。     

Superconducting silver brazing alloy (silver solder)

A superconducting transition has been observed in a type BAg-3 silver brazing alloy (silver solder) with T(c)=96.(6) mK and H(c)=4.7 Oe. The associated diamagnetism indicates that approximately 1/3 of the sample volume displays the Meissner effect. This property dictates caution in its use at very low temperatures, particularly near sensitive magnetic devices such as ac and SQUID magnetometers.     

无氰镀银工艺研究

针对原使用的氰化镀银工艺存在的有害环境及健康情况,开展了无氰镀银工艺研究。在研究过程中使用退火的SAE4340钢试片通过交叉试验确定硫代硫酸盐镀银相关工艺参数,对镀后镀层质量、结合力、焊接性能、电阻、防腐蚀性能及耐高温性能进行了测试,并与使用氰化镀银工艺的同材质钢试片镀后各项性能进行了比较,确定了适合使用的硫代硫酸盐镀银工艺。     

Electroless silver coating of rod-like glass particles

An electroless silver coating of rod-like glass particles was performed and silver glass composite powders were prepared to impart electrical conductivity to these non-conducting glass particles. The low density Ag-coated glass particles may be utilized for manufacturing conducting inorganic materials for electromagnetic interference (EMI) shielding applications and the techniques for controlling the uniform thickness of silver coating can be employed in preparation of biosensor materials. For the surface pretreatment, Sn sensitization was performed and the coating powders were characterized by scanning electron microscopy (SEM), focused ion beam microscopy (FIB), and atomic force microscopy (AFM) along with the surface resistant measurements. In particular, the use of FIB technique for determining directly the Ag-coating thickness was very effective on obtaining the optimum conditions for coating. The surface sensitization and initial silver loading for electroless silver coating could be found and the uniform and smooth silver-coated layer with thickness of 46nm was prepared at 2mol/l of Sn and 20% silver loading.     

Loss of silver grains from completed autoradiographs

The rapid loss of silver grains from processed autoradiographs has been traced to the use of unsatisfactory dehydrating reagents and mounting media.     

镀银保持架变色分析

为提高轴承的自润滑能力,延长轴承使用寿命,车制保持架采用镀银方法进行表面化学处理。镀银质量的好坏直接影响到轴承质量。     

Microstructural investigation of colloidal silver embedded in glass

Nanoparticulate composites consisting of very small silver particles embedded in near-surface regions of glass were obtained by sodium–silver ion exchange. Colloidal silver is formed by reduction of silver ions and aggregation of silver atoms in the glass matrix at elevated temperatures. Owing to absorption bands in the visible region, the silver particles cause a coloration of the glass that depends on their size and depth distribution. From high-resolution electron microscopy imaging of lattice plane fringes of the silver particles, size-dependent lattice contractions are deduced that are larger than those reported in the literature for supported particles not interacting with a matrix. This effect is the more pronounced the higher the annealing temperature is during the particle formation. The increased lattice contraction is attributed to compressive stresses that arise during the ion exchange process as well as during cooling after annealing.     

Low-frequency Raman scattering of light by silver nanoparticles

Silver nanoparticles sprayed onto a crystalline quartz substrate are characterized by means of the low-frequency Raman scattering. Contributions of silver nanoparticles of different sizes to the Raman scattering spectrum are estimated. Data of scanning electron microscopy are used to verify the validity of the results obtained.