超声-伏安法对饮用水中痕量铅(Ⅱ)和铜(Ⅱ)的检测研究

以金纳米粒子修饰玻碳电极为工作电极,采用超声-微分脉冲阳极溶出伏安法连续测定饮用水中痕量铅(Ⅱ)和铜(Ⅱ).通过原子力显微镜(AFM)对金纳米粒子的形貌和大小进行表征,对超声波提高伏安检测信号的工作机理作了比较详细的探讨.实验结果表明,超声波-伏安法提高了方法的灵敏度,与传统的微分脉冲伏安法相比,Pb(Ⅱ)和Cu(Ⅱ)的峰电流分别增大10倍和8倍.Pb(Ⅱ)和Cu(Ⅱ)离子在质量浓度10～250 μg·L-1和5～200 μg·L-1范围内成良好的线性关系,相关系数分别为0.9943和0.9985.在含有50 μg·L-1 Pb(Ⅱ)和20 μg·L-1 Cu(Ⅱ)的溶液中重复测定9次,其相对标准偏差为3.5%和2.2%,Pb(Ⅱ)和Cu(Ⅱ)的检出限分别为0.3 ng·mL-1和0.1 ng·mL-1.该方法成功应用于饮用水中痕量Pb(Ⅱ)和Cu(Ⅱ)的检测,方法简便可靠,具有实际应用意义.     

基于电化学方法测定饮用水源水中的痕量铜离子

本文建立了一种饮用水源水中痕量溶解态铜离子（Cu²⁺）的定性和定量电化学检测方法. 该方法首先通过电化学循环伏安法于玻碳电极表面制备粒径约为70 nm的金纳米粒子（Au NPs）,然后采用方波阳极溶出伏安法进行待测水样中Cu²⁺的定性定量分析. 研究结果表明,对于标准溶液,方法的检出限为1.3μg·L^-1,线性范围在2 ~ 50μg·L^-1之间,常见重金属离子对其定性定量分析几无影响. 在此基础上,将该方法应用于福建省重要的饮用水源水--闽江中游水样中Cu²⁺的含量分析,所得测试结果与国家标准方法（石墨炉原子吸收光谱法）无显著性差异,标准偏差在20%以内. 本方法具有电极制备简单、测定成本低以及分析快速等优点,进一步优化电极制备方法以提高方法的重现性和定量准确度,将可望用于现场测定各种饮用水源水中的痕量溶解态Cu²⁺.     

溶出伏安法同时测定矿山地下水中痕量砷铅

本文以电化学预处理的金电极为工作电极,采用线性扫描溶出伏安法实现了矿山地下水中痕量As3+、Pb2+的同时测定。研究了金电极的预处理方法、不同预富集时间和不同电解质对重金属离子测定的影响规律。研究发现,电化学预处理有利于金电极对重金属离子的响应,在最优实验条件下,As3+、Pb2+在电化学活化的金电极上分别于0.18V、-0.07V产生灵敏的溶出峰,峰高与其浓度线性相关,检测限分别可达到0.5!g/L、2!g/L。该方法操作简单、干扰小、线性范围宽、灵敏度高。     

2.5次微分溶出伏安法同时测定人脑中铜,铅,镉,锌

本文通过硝酸－硫酸混合酸消化脑样，在０．０３ｍｏｌ／ＬＨＣｌＯ４底液中，采用悬汞电极２．５次微分阳极溶出伏安法同时测定人脑中铜、铅、镉、锌四种微量元素。在选定的实验条件下，所述元素的浓度在５～１００ｎｇ／ｍＬ范围内与峰高成线性关系。用于人脑中铜、铅、镉和锌的分析，其相对标准偏差分别为６．５％、１０．５％、１２．７％和３．１％，其回收率为９８．０％、９４．０％、１０２．０％和１０４．０％。     

溶出伏安法测定乌药中的铜铅镉

在KNO3底液下,用线性扫描阳极溶出伏安法同时测定了乌药样品中铜、铅、镉3种金属的含量.结果表明,在最佳实验条件下,铜、铅、镉的峰电位分别为0.067、-0.45和-0.64V(vs ScE);铜、铅、镉金属离子的质量浓度在0-0.8 mg·L-1范围内,呈现良好的线性关系,相关系数分别为0.991 3、0.990 5...     

方波吸附溶出伏安法同时测定水中痕量铜和镉

报道了应用方波吸附溶出伏安法 (OSWSV)同时测定Cu(Ⅱ )和Cd(Ⅱ )。在 0 .0 1mol·L- 1酒石酸钾钠 2 .0× 10 - 4mol·L- 1水杨醛肟溶液中 (pH 11.75 ) ,Cu(Ⅱ )和Cd(Ⅱ )分别与水杨醛肟形成的络合物均产生非常灵敏的还原波 ,峰电位分别为 - 0 .5 5 6V和 - 0 .70 4V (vs.Ag/AgCl以下均同 )。峰电流与Cu(Ⅱ )、Cd(Ⅱ )浓度分别在 9.0× 10 - 74 .0× 10 - 8mol·L- 1和 2 .0× 10 - 6 6 .0×10 - 8mol·L- 1范围内呈线性关系 ,检出限均为 1.0× 10 - 8mol·L- 1。该法用于同时测定水样中痕量Cu(Ⅱ )和Cd(Ⅱ ) ,所得结果满意。通过对该体系的初步研究 ,Cu(Ⅱ )、Cd(Ⅱ )与水杨醛肟形成的络合物的还原峰具有明显的吸附性。     

Inkjet Printed Multi‐walled Carbon Nanotube Sensor for the Detection of Lead in Drinking Water

Electroanalytical methods can be used for the reliable detection of the toxic heavy metal lead in drinking water samples. Inkjet printed electrodes have potential for the rapid and affordable assessment of drinking water. Researchers have shown the electrochemical sensing applicability of inkjet printed electrodes. In this work, Pb²⁺ was detected using an inkjet printed multi‐walled carbon nanotube (IJP‐MW‐CNT) electrode with silver tracks printed underneath. The silver tracks provide the sensor with the conductivity needed for sensitive measurements. MW‐CNT were dispersed in water using bile salts as a surfactant to prepare the ink. The IJP‐MW‐CNT electrode was used as the working electrode with a platinum wire and Ag/AgCl as auxiliary and reference electrode, respectively. The electrodes performance was optimized in 0.1 M acetate buffer (pH=4.3) and had two linear ranges of 5 to 20 ppb (R²=0.99) with a sensitivity of 38 nA/ppb and 20 to 50 ppb (R²=0.98) with a sensitivity of 15 nA/ppb and a limit of detection (LOD) of 1.0 ppb for Pb²⁺. The analytical applicability of electrode was determined by constructing a calibration curve in an unaltered drinking water sample (i. e.) Cincinnati tap water with two linear ranges of 15 to 40 ppb (R²=0.99) with a sensitivity of 1.5 nA/ppb and 40 to 70 ppb (R²=0.99) with a sensitivity of 3.5 nA/ppb and a LOD of 1.0 ppb for Pb²⁺. Effects of copper and cadmium as potential interferents are reported.     

Determining Trace Concentrations of Copper in Water by Cathodic Film Stripping Voltammetry with Adsorptive Collection

Abstract

A technique is presented for the determination of trace concentrations of copper (II) in natural water samples by cathodic stripping voltammetry of a film of copper-catechol complex ions adsorbed on the hanging mercury drop electrode. The peak height of the copper-catechol reduction peak is linearly dependent upon the copper (II) concentration between 10^?10 and 10^?7 M. The detection limit of the technique is below 10^?10 M copper (II) for a collection time of 3 minutes, but the sensitivity can be further increased four-fold by collecting for 15 minutes. The sensitivity is reduced by high concentrations of competing trace metals and of surfactants, which necessitate the use of standard additions to the sample.     

Adsorptive Cathodic Stripping Voltammetry Determination of Ultra Trace of Lead in Different Real Samples

Abstract

In the present work, an adsorptive cathodic stripping voltammetric method using a hanging mercury drop electrode (HMDE) was described in order to determine the ultra trace of lead ions with carbidopa in different real samples. The method is based on accumulation of lead metal ion on mercury electrode using carbidopa as a suitable complexing agent. The potential was scanned to the negative direction and the differential pulse stripping voltammograms were recorded. The instrumental and chemical parameters were optimized. The optimized conditions were obtained in pH of 8.4, carbidopa amount of 1.0×10^?6 M, accumulation potential of 0. 0 V, accumulation time of 100 s, scan rate of 100 mV/s and pulse height of 50 mV. The relationship between the peak current versus concentration was linear over the range of 2.4×10^?10–4.8×10^?7 M. The limits of detection were 5.8×10^?11 M and the relative standard deviation at 4.8×10^?10, 2.1×10^?8, and 2.4×10^?7 M of lead ion were obtained 3.2, 2.9, and 2.7%, respectively (n=7).     

微波消解-溶出伏安法对食品中铜、铅、镉的同时测定

采用微波消解结合同位镀汞阳极溶出伏安法对茶叶、紫菜和西洋菜等食品中的铜、铅、镉进行了测定,并优化了微波消解、电解缓冲液、富集电位等实验条件。采用标准加入法定量,Cu、Pb、Cd的线性范围分别为0.040~1.768、0.080~1.768、0.040~1.768 mg/L,相关系数分别为0.998 4、0.998 2、0.997 0,检出限分别为0.008、0.016、0.008 mg/L,相对标准偏差(n=5)分别为4.1%、0.92%、2.0%。该方法测定茶叶、紫菜、西洋菜等实际样品的铜、铅、镉含量,加标回收率分别为98%~109%、94%~103%、100%~112%;将测定结果与原子吸收光谱法检测结果对比,表明此方法简便、快速,且具有较高的灵敏度、较好的选择性和可靠性。     

痕量铅在草酸修饰电极上阳极溶出伏安的研究

本文对草酸修饰电极的制作、痕量铅在草酸修饰电极上的反应机理和电化学特性作了研究。采用阳极溶出伏安法,测定铅的灵敏度比玻碳电极提高7.5倍,在1.0～15.0ng·/mL铅浓度范围内溶出峰高与铅浓度呈良好的线性关系。连续测定12次变异系数为3.0％。利用草酸修饰电极对人尿中痕量铅进行了测定,结果良好。     

Copper (II), Lead (II) and Cadmium (II) Complexes with the Antiinflammatory Drugs Piroxicam and Tenoxicam

Abstract

The chelating tendency of the antiinflammatory drugs piroxicam and tenoxicam towards copper (II), lead (II) and cadmium (II) ions has been investigated using both differential pulse polarography and cyclic voltammetry and the stability constants of the formed complexes have been compared. The effect of the nature of the supporting electrolyte, the pH and other parameters have also been considered.

Tenoxicam exhibits relatively stronger chelating properties than piroxicam towards each ion despite of their structural similarity.     

微分电位溶出法连续测定人发中锌、铜、铅、镉

本文报道了连续测定人发中痕量锌、铜、铅、镉的微分电位溶出法。实验确定最佳支持电解质组成为1M HAc-0.4M KCl-1.5×10~(-2)M Hg(Ⅱ)。在此体系中测定上述四种元素的分辨率好,峰形好,灵敏度高,重现性好。试验了共存离子的影响,方法干扰少,回收率为96.7～105%,测试范围从ppb到ppm级。