吸附溶出伏安法测定海水中镍、钴条件优化研究

通过实验对吸附溶出伏安法测定海水中镍、钴测定条件进行了探索,筛选出了最佳的化学实验条件。最佳条件为:氨水-氯化铵(1 mol/L)-丁二酮肟(0.01 mol/L)体系为电解质溶液,用氨水溶液(27.5+72.5)调节体系pH值在8.0～9.5之间后,加入0.05 ml的丁二酮肟(0.01 mol/L)进行测试。镍、钴的方法检出限能分别达到0.4μg/L、0.1μg/L,方法精密度准确度良好。     

阴极溶出伏安法测定水中痕量硫化物

本文介绍了０．１５ＭＮａＯＨ、０．００２ＭＥＤＴＡ－Ｎａ２底液中，阴极溶出伏安法测定水中痕量硫化物的方法。扫描电位－０．３～－１．０Ｖ，溶出峰电位约－０．６５Ｖ，在０．０１６～０．１６ｍｇ／Ｌ范围内呈线性，相关系数ｒ＝０．９９３，检测下限可达０．００４ｍｇ／Ｌ。方法简便、迅速。     

1.5次微分阴极溶出伏安法测定水泥中微量氯

采用悬汞电极－甘汞电极－铂对电极三电极系统,建立了１．５次微分阴溶出钛安法测定水泥中微量氯的分析方法。本法适用于７．５×１０＾－６￣９．５×１０＾－６ｍｏｌ／ＬＣｌ＾－样品的测定,样品预处理手续简单,无需除氧,是一种快速简便,准确精密的方法。     

阳极溶出伏安法同时测定水中微量砷、汞的研究

采用微分脉冲阳极溶出伏安法同时测定了水中微量As和Hg。三电极系统以金盘电极为工作电极,以添加了盐酸羟胺的硫酸溶液为电解液。通过响应峰高的比较,找到了目标元素富集和溶出的最佳试验条件。在10-60μg/L的范围内As和Hg都线性良好,相关系数能达到0.997以上,相对标准偏差均小于3%。     

方波溶出伏安法同时测定水体中的重金属

应用方波溶出伏安法同时测定水体中几种微量重金属离子浓度,在浓度为8.0g/L的氯化铵底液中,合适的条件和参数下,Mn2+、Zn2+、Hg2+均灵敏地产生溶出峰。峰电位分别为:-1.94V、-1.05V、1.31V。此方法灵敏度高,检测限低,重现性好,适合进行微量重金属离子的快速同时检测。     

吸附溶出伏安法同时测定电站锅炉用水中的痕量铜、铁

建立了吸附溶出伏安法同时测定痕量铜、铁的方法.以邻苯二酚为配合剂,哌嗪-1,4-双(2-乙烷磺酸)(PIPES)为缓冲溶液,在最优条件下,对铜离子的测量范围为0～35μg/L相关系数r=0.999 4;对铁离子的测量范围为0～30μg,L,相关系数r=0.998 0.两者的检测限分别为0.069、0.407μg/L.此法应用于电站锅炉用水中痕量铜、铁的测定,回收率分别为103.6%和104.7%.说明该法不仅灵敏度高、准确性好.而且操作简单、快速.     

碳糊电极溶出伏安法同时测定废水中两种酚类污染物

通过自制碳糊电极的阳极溶出伏安法,富集与测量相结合,同时测定了胶片洗印废水中的痕量对甲氨基苯酚硫酸盐和１,４－二羟基苯,并对碳糊电极的富集机理作了探讨。     

微分电位溶出法测定微量镍

研究了水、尿、血中微量镍的测定方法。以丁二酮肟作显色剂,采用分光光度法和微分电位溶出法作比较,得知后者操作简便,灵敏度和回收率高于前者。     

阳极溶出伏安法测定牙膏中的痕量铅

牙膏样品用HNO3-H2O2分解后,采用汞膜玻碳电极阳极溶出伏安法测定试样中的痕量铅。方法的回收率为96-106%,相对标准偏差为5.7%     

利用超声波阳极溶出伏安法测定痕量汞

以阳极溶出伏安法研究了超声波作用下汞在金电极上的电化学行为,建立了痕量汞的超声波-阳极溶出伏安法。采用超声波增加了汞的溶出峰电流,提高了方法的灵敏度,在优化实验条件下,汞离子浓度在0～25μg/L范围内,线性方程为I=1.08c+0.27,(μg/L,R=0.998),加入标准汞溶液为6μg/L时,测量值的重复性和精确度都在5%以内。常见金属离子一般不干扰,方法简便快速。     

臭氧消解技术在水样重金属测定中的应用

阳极溶出伏安法是测定水样中痕量重金属的常用方法,但水样中的有机胺等干扰物严重影响该方法的定性和定量。采用臭氧消解技术对加入模拟干扰物的水样和排污口水样进行了消解,并对铜、锌、铅、镉等元素进行了测定。结果表明,该方法对干扰物有较好的去除效果,方法的准确度和精密度较好,并且操作简便、高效,易于实现自动化。     

Determination of trace selenium by differential pulse adsorptive stripping voltammetry at a bismuth film electrode

The differential pulse adsorptive stripping voltammetric behavior of selenium (IV)-p-aminobenzene sulfonic acid-cetyltrimethylammonium bromide system at a bismuth-coated glassy carbon electrode (BiFE) has been investigated. A well-defined and sensitive stripping peak of the selenium (IV)-p-aminobenzene sulfonic acid complex was observed at −0.76 V (vs. SCE) in a 0.15 mol/L acetate solution (pH 2.9) at a deposition potential of −0.40 V (for 120 s). The linear range was 2-30 μg/L and the detection limit for an accumulation time of 300 s was 0.1 μg/L. This method was applied to determine the trace amount of selenium in the samples.     

铋膜电极微分脉冲溶出伏安法测定食用明胶中的铅

通过铋膜修饰的玻碳电极,建立了明胶中铅的差分脉冲溶出伏安分析法。结果表明,在pH=4.0的HAc-NaAc缓冲介质中,-1.0 V富集300 s后,溶出峰电流与Pb2+浓度在50~1 000μg/L范围内呈线性关系,相关系数r=0.995 6,在实际样品测量中,回收率在97.75%~104.79%,相对标准偏差为2.20%。     

Detection of trace levels of Pb in tap water at boron-doped diamond electrodes with anodic stripping voltammetry

Boron-doped diamond (BDD) electrodes were used to investigate the possibility of detecting trace levels of lead by linear-sweep anodic stripping voltammetry. The low limit of detection (2 nM) is an advantage compared to other electrode materials, and it was found that at low pH values, copper concentrations that are usually present in drinking water do not affect to a large extent the detection of lead. These findings recommend anodic stripping voltammetry at the BDD electrodes as a suitable mercury-free method for the determination of trace levels of lead in drinking water. The results obtained for the lead detection in tap water real samples are in excellent agreement with those found by inductively coupled plasma-mass spectrometry (ICP-MS), demonstrating the practical analytical utility of the method.     

Simultaneous determination of trace aluminum (III), copper (II) and cadmium (II) in water samples by square-wave adsorptive cathodic stripping voltammetry in the presence of oxine

A validated adsorptive cathodic stripping voltammetry method is described for simultaneous determination of Al(III), Cu(II) and Cd(II) in water samples. In acetate buffer (pH 5) containing 10 μM oxine, these metal ions were determined as oxine complexes following adsorptive accumulation onto the HMDE at −0.05 V versus Ag/AgCl/KCl_s. The best signal to noise ratio was obtained using a square wave of scan increment 10 mV, frequency 120 Hz, and pulse-amplitude 25 mV. Limits of detection as low as 0.020 μg L⁻¹ Al(III), 0.012 μg L⁻¹ Cu(II) and 0.028 μg L⁻¹ Cd(II) were achieved. Interference due to various cations (K(I), Na(I), Mg(II), Ca(II), Mn(II), Fe(III), Bi(III), Sb(III), Se(IV), Pb(II), Zn(II), Ni(II), Co(II)), anions (Cl⁻, NO³⁻, SO₄ ²⁻, PO₄ ³⁻) and ascorbic acid was minimal as the measured signals change by 4% at the maximum. The stripping voltammetry method was successfully applied for simultaneous determination of Al(III), Cu(II) and Cd(II) in tap and natural bottled water samples.     

微分脉冲阳极溶出伏安法测定氢溴酸右美沙芬

应用循环伏安法和微分脉冲阳极溶出伏安法在玻碳电极上对氢溴酸右美沙芬的伏安行为进行了研究。实验结果表明,在pH6.5的B-R(Britton-Robinson)缓冲底液中,氢溴酸右美沙芬在+1.01 V(vs.Ag/AgCl)处有一明显的氧化峰,在4.0×10-6~8.0×10-5mol/L范围内与峰电流呈良好的线性关系(r=0.995 1),检出限为5.6×10-7mol/L。用该方法对氢溴酸右美沙芬片进行了测定,回收率为98.6%~102.9%,结果令人满意,还对其电极反应机理进行了初步探讨。     

铋膜电极差分脉冲溶出伏安法测定苯甲酸钠中的铅

通过铋膜修饰的玻碳电极,建立了苯甲酸钠中铅的差分脉冲溶出伏安分析法。实验结果表明,在pH 4.0的HAc-NaAc缓冲介质中,-1.1 V富集300 s后,溶出峰电流与Pb2 浓度在5-1 000μg/L范围内呈线性关系,相关系数r=0.995 6,在实际样品测量中,回收率在95.4%-103.5%之间,相对标准偏差为3.44%。     

方波阳极溶出伏安法同时测定蔬菜中铜铅含量

蔬菜样品洗涤干燥,在450～500℃灰化12h,加HClO4消解。在0.05mol·L-1的HClO4底液中,以悬汞电极为工作电极,用方波阳极溶出伏安法同时测定蔬菜中Pb、Cu的含量。峰电位分别为:-0.32W、0.10V(vs.Ag/AgCl),此方法的回收率为96%～102%。方法操作简便快捷,准确性好,结果令人满意。     

A study of in situ plated tin-film electrodes for the determination of trace metals by means of square-wave anodic stripping voltammetry

This work is a study of tin-film electrodes (SnFEs) for the determination of trace metals by means of square-wave anodic stripping voltammetry (SWASV). SnFEs represent a new promising type of environment-friendly electrodes but their analytical performance has not been explored in detail so far. Initially, the operational parameters for the simultaneous determination of Cd(II) and Zn(II) on in situ plated SnFEs on different substrates were thoroughly investigated. Using the selected conditions, at a preconcentration time of 120 s the limits of detection were 0.7 μg l⁻¹ for Cd and 0.9 μg l⁻¹ for Zn and the percent relative standard deviations were 4.2% for Zn(II) and 3.6% for Cd(II) at the 20 μg l⁻¹ level (n = 8). Subsequently, a study was conducted to investigate the utility of SnFEs as sensors for the determination of other metals, including those with oxidation potentials close to, or more positive than, the oxidation potential of Sn (Tl(I), Pb(II), Cu(II)). Finally, the SnFEs were successfully applied for the determination of Pb(II) and Zn(II) in tap water.