离子选择电极流动注射分析同时测定钾和氯

1　引　　言在土壤、饲料、生物组织液分析中 ,钾和氯的测定非常普遍 ,人们常用光度分析、ＩＳＥ电位分析。烟草中的钾和氯含量影响其燃烧性能 ,与焦油量直接相关 ,是烟草成份的必检项目。研究一种快速、自动的分析方法很有意义。作为一种动态测量和检测技术 ,ＦＩＡ已多用于物质含量的检测和过程参数的测量 ,ＩＳＥ ＦＩＡ测定单个离子的含量亦有报道。本实验成功地实现了钾和氯离子的ＩＳＥ ＦＩＡ同时测定 ,方法简单快速。2　原　　理采用两支不同体积的进样管向流路中分别载入ＫＣｌ标准溶液 (Ｃ0 ) ,由于进样体积的差异导致标准溶液具…     

聚氯乙烯膜碘离子选择电极在溴碘离子共存体系分析中的应用

介绍了聚氯乙烯膜碘离子选择电极(PVC-I-ISE)的制备方法,电极对碘离子的能斯特响应斜率为59 mV/pI,响应的线性范围为4.0×10-5~1.0×10-2mol.L-1,检出限为1.6×10-5mol.L-1,低于用银ISE的检出限,电极的使用寿命为一个月以上。将制备的碘离子选择电极作为指示电极用于对溴、碘混合离子体系进行连续分别电位滴定,并与以银电极为指示电极的电位滴定方法进行了比较。结果表明用PVC-I--ISE作指示电极,可在I--Br-共存的混合溶液中进行两离子的连续电位滴定,而用银-ISE时则不能。     

溶胶凝胶溴离子选择电极的研制与应用

报道了一种以溶胶凝胶为载体的溴离子选择电极。电极信号响应线性范围为1 .0× 1 0 - 1～ 1 .0× 1 0 - 5mol/L,斜率为 5 7m V/pc;检出限为 2 .5× 1 0 - 6 mol/L。该电极响应快 ,体积小 ,稳定性和重现性好。电极用作测定溴离子浓度 ,结果令人满意     

五氯苯酚离子选择电极的研制

本文报道以三庚基十二烷基铵与三氯苯酚离子缔合物为电极活性物制备的PVC膜五氯苯酚离子选择电极。该电极具有Nernst响应范围宽2×10~(-5)M～1×10~(-1)M、灵敏度高.斜率S为60、检测下限低5×10~(-6)M、选择较好、响应时间短等特点、且电极连续工作电势读数稳定性好等优点。适用于自动监测及电位滴定分析。     

基于碘离子选择性电极的流动注射分析系统构建

碘硫(IS)热化学循环分解水是目前最有前景的核能制氢技术.在IS循环研究中,I-浓度的在线分析对于实现过程反应条件的监测控制以及进行有关反应动力学研究非常重要.以碘离子选择性电极为检测器,针对IS循环物料组成体系组装了一套流动注射分析系统,考察了样品温度、氢离子浓度、离子强度等因素对电极性能的影响,对FLA装置的栽流流...     

氯胺T氧化-酚红分光光度法测定含碘卤水中溴

卤水中微量溴离子常采用荧光素分光光度法测定[1],该法对时间的要求较为严格,操作较繁琐,测定含碘卤水中的溴离子重现性较差。酚红分光光度法测定[2]卤水中的溴离子,碘对其测定干扰较大。本工作在文献[3]基础上,采取措施消除碘的干扰,     

用氯离子选择电极同时分析水中Cl~－、Br~－、I~－的含量

本文研究了氯离子选择电极同时测定水中Ｃｌ￣－、Ｂｒ￣－、Ｉ￣－的方法。利用氯电极对Ｂｒ￣－、Ｉ￣－的响应，用混合加入法测定，非线性最小二乘法计算求解。测定了实际体系中Ｂｒ￣－、Ｉ￣－在氯电极上的选择系数，然后用多次标准加入法测定，迭代法同时计算各组份的分析结果，从而实现了用氯电极同时分析水中Ｃｌ￣－、Ｂｒ￣－、Ｉ￣－的含量。     

Fabrication of a Nitrate Selective Electrode for Determination of Nitrate in Fertilizers by Using Flow Injection Analysis System

A nitrate ion selective electrode (nitrate-ISE) based on pyrrole modification on a common pencil lead was proposed. The lab-made nitrate-ISE was easily constructed by pyrrole polymerization with nitrate ion as the dopant using cyclic voltammetry. The fabricated nitrate-ISE was then coupled with flow injection analysis (FIA) for an automatic system. The flow potentiometry provided working range of 1x10^-4 to 4x10^-3 mol L^-1 of nitrate and allowed sample throughput up to 50 samples h^-1. Linear regression analysis showed good agreement (r²=0.9961) with Nernstian response. This system was applied to determine nitrate-nitrogen (nitrate-N) in fertilizer samples.     

流动分析-离子选择电极法测定水中痕量氟化物

基于流动分析-离子选择电极技术,建立了一种测定水中痕量氟化物的分析方法。体系使用注射泵将注入的样品推出,在稳态的条件下进行测定。样品与总离子强度缓冲溶液(TISAB)等体积混合后,采用蠕动泵注入样品,注入量为400L。采用注射泵驱动载流速度快,比蠕动泵效果好。载流为0.05mg/L F-标准溶液,采用奥立龙(Orion)电极,倾斜20°的喷壁型(Wall-jet)流通池。样品之间插入清洗,方法没有交叉携出。在最佳的条件下,方法的线性范围为0.05～1.0mg/L,检出限为0.015mg/L,RSD为1.5%(0.2mg/L)。样品分析频率为30样/h。本方法对质控样品的测定结果令人满意。3个水样的加标回收率为96.8%～104.5%。用4个水样与国标中的手工分析方法进行了对比,在95%的置信区间内,配对t检验结果无显著差异。本方法灵敏度高,分析速度快、试剂消耗少,废液排放量低,适用于水中低浓度样品的分析。     

微酶电极的研制及在流动注射分析中的应用

利用铂化电极的大表面吸附葡萄糖氧化酶（简称ＧＯＤ）构建了一种具有良好操作性能的微酶电极，在０～１０ｍｍｏｌ／Ｌ葡萄糖浓度具有很好线性，相关系数γ＝０．９９８，响应时间短（＜２０ｓ），精度高。利用该电极组成三电极流动注射分析系统，这种系统同样有较好的线性范围，分析频率达４５ｈ＾－１，使用寿命在一周以上。     

流动注射分析用新型钆离子电极

功能高分子为活性材料,加热压片,制成新型钆电极。其性能较PVC式钆离子选择电极为优。取钆电极膜片制成流通式钆电极,与流动注射仪联用,测得电极斜率59mV,与静态响应相似。每次进样500μl,测定频率每小时60～100次。操作简单,重现性好。     

Automated Determination of Captopril by Flow and Sequential Injection Analysis: A Review

The present study intends to present a review of automated methods for the determination of Captopril—an angiotensin converting enzyme (ACE) inhibitor—using flow or sequential injection analysis. The review covers a range of more than fifteen years of published research on this topic (1993–today). The methods are classified according to the detection systems in three categories, namely spectrophotometric, chemiluminescence, and electroanalytical. The principles and main analytical figures of merit of the reported studies are presented and discussed.     

壁喷电池在流动注射阳极溶出伏安法中的应用

在流动注射阳极溶出伏安法中应用壁喷电池,探讨了非稳定态电积过程的溶出峰电流理论方程,预言了峰电流正比于R~(3/4)(R为工作电极半径),并对有关参数进行了实验验证。对5×10~(-7)mol/L Cd(Ⅱ)连续测定40次,表明相对标准偏差为0.94％。     

Flow Injection Analysis of Lactate and Lactate Dehydrogenase Using an Enzyme Membrane in Conjunction with a Modified Electrode

Abstract

A modified electrode for H₂O₂ oxidation, consisting of Pd/Au sputtered on carbon was covered with a lactate oxidase membrane and used in a FIA manifold for selective determination of lactate. The linear range was 0.01-3 mM lactate and up to 200 samples per hour were measured with a relative standard deviation of 1%. Interferences from ascorbic acid and NADH were small because of the low potential of the modified electrode. The lactate oxidase membrane electrode was also used for measurement of lactate dehydrogenase activity using direct injection of the sample into a carrier stream containing pyruvate and NAD⁺.     

Bismuth Film Electrode for Analysis of Tetracycline in Flow Injection System

A bismuth film was prepared on glassy carbon electrode (GCE) and used in a flow injection amperometric system to analyze tetracycline. Bismuth film electrode (BiFE) preparation and flow injection amperometric parameters were optimized. System performances of BiFE were compared to GCE. BiFE was validated with three different lots of real sample, 250 mg tetracycline capsules, the results showed good agreement, i.e., between 240 and 260 mg per capsule. Good relative recoveries were also obtained in the range of 86–106%.     

Determination of Nitrite With A Ptfe-Membrane,Covered Electrode After Reduction To Nitrogen Oxide,In A Reagent Saving Flow Injection System

ABSTRACT

Nitrite was reduced in acidic potassium iodide solution to produce nitrogen oxide which was measured amperometrically by a modified gold electrode covered with a PTFE-membrane as the permeability barrier for interfering substances in the sample. The calibration curve was linear up to 30 μM of nitrite and 10 samples could be determined per hour. The average current and the standard deviation for 10 μM standard solution (N=10) were 1.51 x 10^-2 μA and 6.4 x 10^-5 μA (RSD=0.42 %), respectively. The detection limit was 0.25 μM. No response was observed for electrochemical interferant substances such as ascorbic acid and FeSO⁴. The reducing reagent could be reused. Recovery tests were satisfactory (101-103%). The results obtained with this sensor and with the diazotization method for a fish culture water agreed within 8.6%.     

Flow Injection Analysis System Using Magnetic Beads,Screen Printed Electrodes and Magnets

Here is presented a Flow Injection Analysis (FIA) system using a flow cell with an integrated magnet, applied to biotin determination. The mixture of magnetic beads modified with streptavidin (Strep‐MB), biotin and B‐HRP is left 15 minutes under stirring and then a washing step is performed in an automatic way thanks to the external magnets coupled in the FIA system. After the immobilization of the MBs on the surface of the electrode, 3,3′,5,5′‐Tetramethylbenzidine (TMB) is injected. The linear range obtained is between 0.5 to 10 pM of biotin and the sensitivity is 85 nA/pM.