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…     

简易型离子选择电极-流动注射分析仪的研制及卤水中氯、溴和碘的连续测定

本文设计研制了简单实用的流通池,组装了简易型离子选择电极—流动注射分析仪,对体系的分析特点和影响因素进行了考察。此装置性能可靠,能满足简单流注分析的需要,并建立了卤水中Cl~-、Br~-和I~-的连续测定方法。     

同时测定海水中K+、Na+、Ca2+、Cl-的流动注射离子选择电极分析

建立了一种用于海水中K+、Na+、Ca2+、Cl-同时快速、自动测定的流动注射离子选择电极自动方法(FI-ISE-M),优化了方法的最佳条件:总离子强度调节液(TISAB)的组成为0.3 mmol/L K+、6.0 mmol/L Na+、1.4 mmol/L Ca2+、21.0 mmol/L Cl-及pH8.0的80 mmol/L的tris-H3BO3缓冲溶液,其流量为1.25mL/min;每次测定的样品用量仅为160μL,载流流量为1.42 mL/min,混合盘管长度为30cm(I.D.0.5 mm)。本方法的分析速度为100样/h,相对标准偏差为2.0%(n=11),标准添加回收率为94.9%～104.3%,测定范围分别为1.0～8.0 mmol/L K+、50～290 mmol/L Na+、3.2～16.0 mmol/L Ca2+、70～430 mmol/LCl-。本方法已应用于反渗透海水淡化系统的水质检测。     

PVC基管状流通钾离子选择电极的研制及其在流动注射分析中的应用

实验装置由PVC基管状流通钾离子选择电极和与它结合的流动注射分析体系两部分组成。对该体系的分析特点和影响测定的参数进行了讨论,建立了土壤浸提液中钾测定方法,样品分析结果和火焰光度法有良好一致性。     

同时测定血清中4种电解质的流动注射微电极串联电化学自动分析系统

基于流动注射-微电极串联的动态电化学技术,建立了能快速、自动、同时测定血清中K(+),Na(+),Cl(-)和Ca(2+)的分析方法和系统,并成功用于血清样品的测定.为稳定4种电极的基线电位、加快电极响应速度,优化了载流的组分:23mmol/L Na2B4O7-H3BO3(pH 7.40),0.25mmol/L K(+...     

流动注射-原子吸收光谱法测定血清中的钾、钠、钙和镁

本文报道了血清试样经50倍稀释后,选择适当的实验参数,在同一试液中用流动注射-原子吸收光谱法测定钾、钠、钙和镁。在载流流速为8ml/min时,进样频率达300次/小时,每次进样40μl(相当于血清0.8μl)。测定的相对标准偏差对钾、钠、钙和镁分别为1.1%,1.2%,1.3%和1.4%。本法用于测定人体血清并与临床分析方法相比较,结果良好。     

碳棒涂膜电极流动注射法测定环境水样中的阴离子表面活性剂

采用自制碳棒PVC涂膜阴离子表面活性剂电极 ,建立了测定环境水样中阴离子表面活性剂的流动注射电位分析新方法。电极膜最佳组成 :THDA DBS 5mg ,DBS 0 .4mL,NB 0 .3mL ,PVC粉 0 .2g;电极线性响应范围 1× 1 0 - 3～ 1× 1 0 - 6 mol L。以 0 .0 1mol LKCl溶液作载流 ,流速 6.6mL min ,进样体积 2 0 0 μL,分散管长 2 0cm ,采样频率 5 0～ 80次样 h。测定 1 0 - 3、1 0 - 4 mol LDBS溶液 ,RSD≤ 3 .1 2 % (n=7) ,回收率 88.0 %～ 1 0 5 .0 %。电极易制作 ,成本低 ,FIA流路简单 ,操作方便 ,且克服了直接电位法电位飘移大的缺点 ,有较好的实用性     

离子选择电极和流动注射分析联用的研究 Ⅰ.超纯水中痕量钠离子的快速测定

把流动注射技术和试制的流通pNa电极联用来测定电子级纯水中的痕量钠,检测下限可达0.1ppb。本方法快速、灵敏。准确而又方便。是目前已知的测量痕量钠的最好方法之一。特别适用于半导体工业和大规模集成电路制备工艺用水中对钠的检测。     

流动注射-分光光度-火焰光度串联技术同时快速测定磷、钾、钠的研究

本文利用流动注射-分光光度-火焰光度串联技术,使磷生成磷钼兰以721型分光光度计检测,钾、钠以6400型火焰光度计检测,从而建立了磷、钾和钠三元素同时快速测定的新方法,该方法操作简单、方便、快速,每小时可进行60次测定,磷、钾、钠兰元素的线性范围分别为1.0～4.0μg/ml、3.0～60μg/ml和6.0～40μg/ml。利用该方法测定了植物样品中的磷、钾和钠,获得了良好的结果。     

Flow injection analysis of potassium using an all-solid-state potassium-selective electrode as a detector

The concentration of potassium was determined by a combination of flow injection analysis (FIA) with an all-solid-state potassium sensor detection. The all-solid-state potassium-selective electrode possessing long-term potential stability was fabricated by coating an electroactive polypyrrole/poly(4-styrenesulfonate) film electrode with a plasticized poly(vinyl chloride) membrane containing valinomycin. The simple FIA system developed in this laboratory demonstrated sensitivity identical to that in the batch system and achieved considerably rapid assay (150 samples h⁻¹). Analyses of soy sauce and control serum samples by this FIA system yielded results in good agreement with those obtained by conventional measurements.     

集成微管路离子选择电极功能块研究

本文对微型管状离子选择电极在流动条件下的电化学特征进行了研究,并设计了新的集成微管路离子选择以电极功能块。用此微型装置测定了土壤、血清、水和药物中的K~+、Na~+、pH、Cl~-、F~-、阿托品、东茛菪碱,并和各种标准方法作了比较,获得满意分析结果。     

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.     

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400"L。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。     

连续流动分析仪法测定水溶肥中氧化钾

采用连续流动分析仪法测定水溶肥中氧化钾含量,并与NY/T 1977-2010进行比较。结果表明,样品溶液中氧化钾在0～400mg/L范围内线性良好,相关系数r=0.9995,与四苯硼酸钾重量法结果比对结果接近,绝对偏差小于0.23%,准确度高,加标回收率在98.2%～100.6%之间,重现性良好,10次重复测定相对标准偏差为0.22%。     

Determination of phosphate in hydroponic nutrient solutions using flow injection potentiometry and a cobalt-wire phosphate ion-selective electrode

The direct flow injection potentiometric (FIP) analysis of phosphate in hydroponic nutrient solution has been carried out using a cobalt-wire ion-selective electrode (ISE). Synthetic hydroponic nutrient solution, commercial hydroponic nutrient solution and working hydroponic farm nutrient solution were analysed for phosphate using the FIP technique. It is shown that FIP results compare favourably to standard methods of analysis such as spectrophotometry and indirect photometric ion-pair chromatography. Reproducible FIP response curves with a slope of −(47.57±0.03) mV per decade and intercept of −(169.7±0.1) mV were obtained for four separate calibrations in the concentration range 5.0×10⁻⁴–1.0×10⁻² M H₂PO₄⁻. Anion corrections for interferences by Cl⁻, NO₃⁻ and SO₄²⁻ were applied to all samples using the selectivity coefficients determined independently using a fixed interference method. Nevertheless, it was found that anion corrections were not necessary, as the deviations fell within the bounds of experimental error for the cobalt-wire ISE technique (i.e.±2–5% R.S.D.). The proposed FIP method enables the direct determination of phosphate in hydroponic nutrient solutions.     

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.     

Study of the Electrochemical Behavior of Disperse Blue 1‐Modified Graphite Electrodes. Application to the Flow Determination of NADH

The preparation and the electrochemical study of Disperse Blue 1‐chemically modified electrodes (DB1‐CME), as well as their efficiency for the electrocatalytic oxidation of NADH is described. The proposed mediator was immobilized by physical adsorption onto graphite electrodes. The electrochemical behavior of DB1‐CME was studied with cyclic voltammetry. The electrochemical redox reaction of DB1 was found to be reversible, revealing two well‐shaped pair of peaks with formal potentials 152 and ?42 mV, respectively, (vs. Ag/AgCl/3M KCl) at pH 6.5. The current I_p has a linear relationship with the scan rate up to 800 mV s^?1, which is indicative for a fast electron transfer kinetics. The dissociation constants of the immobilized DB1 redox couple were calculated pK₁=4 and pK₂=5. The electrochemical rate constants of the immobilized DB1 were calculated k₁°=18 s^?1 and k₂°=23 s^?1 (Γ=2.36 nmol cm^?2). The modified electrodes were mounted in a flow injection manifold, poised at +150 mV (vs. Ag/AgCl/3M KCl) and a catalytic current due to the oxidation of NADH was measured. The reproducibility was 1.4% RSD (n=11 for 30 μM NADH) The behavior of the sensor towards different reducing compounds was investigated. The sensor exhibited good operational and storage stability.     

二乙基二硫代氨基甲酸钠流动注射萃取分光光度法测定矿石中微量铜的研究

本文对二乙基二硫代氨基甲酸钠(铜试剂)-四氯化碳流动注射莘取分光光度法测定矿石中微量铜进行了研究。与手工萃取法相比,本法最大特点是大量Mn~(2+)无干扰。方法操作简便、快速、可靠、毒性小;进样频率为20次/小时,RSD为3.5％。线性范围为O～1.28μg/ml。方法用于测定矿石中微量铜,结果满意。