Detection of Pesticide Metsulfuron-methyl in Drinking Water by Differential Pulse Cathodic Stripping Voltammetry

Differential pulse cathodic stripping voltammetry was used to determine pesticide metsulfuron-methyl on a suspended mercury electrode.Specific experimental parameters,such as the pH of Britton-Robinson buffer,accumulation time,accumulation potential,and initial potential were optimized.The results show that a typical reduction peak appeared when pH was 2.0-4.0 and initial potential ranged from-0.75 to-1.0 V.To obtain the stripping signal of the best reduction peak,it is determined that the best pH was 2.0.The detection limit of the method was only 0.04 mg/L,and it had good selectivity and high accuracy,so the method has high sensitivity.In the analysis of actual drinking water,the recovery rate of metsulfuron-methyl could reach 93%-101%.

Automated Determination of Cd^(2+) and Pb^(2+) in Natural Waters with Sequential Injection Analysis Device Using Differential Pulse Anodic Stripping Voltammetry

An electrochemical flow device has been developed for the determination of heavy metal ions(HMI)in water using multiwalled carbon nanotubes(MWCNTs)/Nafion(NA)/Hg electrode,by mean of diff erential pulse anodic stripping voltammetry coupled with sequential injection analysis.The accuracy of the determination was ensured by the great electrical conductivity of MWCNTs and the high adsorption capacity of Hg.NA was used for MWCNTs immobilization for the long-term application of the electrode.The mercury film was cleaned after determination and another one would form during deposition.A lower limit of detection and a wider determination range of Cd^(2+)and Pb^(2+)could be achieved using the automatically analytical device combining with the MWCNTs/NA/Hg-modified electrode.The real-time monitoring of Cd^(2+)and Pb^(2+)in fresh water using this device continued for 10 days.The results indicated that the method was potential for on-site and real-time determination of HMI in water samples.

Differential Pulse Anodic Stripping Voltammetric Determination of Lead with Heparin Modified Electrode

A novel differential pulse anodic stripping voltammetry for the determination of trace amounts of lead, using a biomacromolecule heparin drop-coated modified glassy carbon electrode, has been described. Pb2+ was deposited on the surface of a heparin-modified electrode at -1.0 V (vs. SCE) via forming Pb2+-heparin and subsequent re-duction at the electrode. In the following step, Pb-heparin was oxidized, and voltammograms were recorded by scanning the potential in a positive direction. Conditions were optimized with respect to the pH of the medium, the mass of drop-coated heparin, accumulation potential and accumulation time. The peak current was proportional to the Pb2+ concentration in the range of 2.0×10-9 to 7.0×10-7 mol/L. The detection limit was 3.0×10-10 mol/L. The relative standard deviation was 4.83% for 1.0×10-8 mol / L Pb2+ (n=10). The developed method has been applied to the determination of Pb2+ in water samples with satisfactory results.

Application of differential pulse stripping voltammetry and chemometrics for the determination of three antibiotic drugs in food samples

A reliable method for simultaneous determination of three antibiotic drugs（levofloxacin,gatifloxacin and lomefloxacin） by differential pulse stripping voltammetry（DPSV） in Britton-Robinson buffer（pH 7.96） was presented.The method is based on adsorptive accumulation of the antibacterial drugs on a hanging mercury dropping electrode（HMDE）,followed by the reduction of the adsorptive species by the technique of DPSV.Optimal conditions,the deposition time of 80 s,the deposition potential of—1250 mV,and the scan rate of 25 mV/s,were obtained.The linear concentration ranges of 0.010-0.080μg/mL were obtained for all these three antibiotic drugs,while the detection limits were 2.38,3.20 and 1.60ng/mL for levofloxacin,gatifloxacin and lomefloxacin,respectively.In this work,chemometrics methods,such as classical least squares（CLS）,partial least squares（PLS）, principle component regression（PCR） and radial basis function-artificial neural networks（RBF-ANN）,were used to quantitatively resolve the overlapping signals.It was found that PCR gave the best results with total relative prediction error（RPE_T） of 7.71%.The proposed method was applied to determine these three drugs in several commercial food samples with spiked method and yielded satisfactory recoveries.

Determination of trace Pb(II), Cd(II) and Zn(II) using differential pulse stripping voltammetry without Hg modification

In this work,we reported a simultaneous determination approach for Pb(II),Cd(II)and Zn(II)atμg L 1concentration levels using differential pulse stripping voltammetry on a bismuth film electrode(BiFE).The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi(NO)3,and its analytical performance was evaluated for the simultaneous determination of Pb(II),Cd(II)and Zn(II)in solutions.The determination limits were found to be 0.19μg L 1for Zn(II),and0.28μg L 1for Pb(II)and Cd(II),with a preconcentration time of 300 s.The BiFE approach was successfully applied to determine Pb(II),Cd(II)and Zn(II)in tea leaf and infusion samples,and the results were in agreement with those obtained using an atomic absorption spectrometry approach.Without Hg usage,the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.

稀土基金属有机框架材料的制备及其对Pb^(2+)的电化学检测

室温下以硝酸钬为金属源,均苯三甲酸为有机配体,通过--步共混法制备出形貌均一的棒状稀土基金属有机框架材料(Ho-MOF),在玻碳电极基底上,采用两步滴涂法制备Ho-MOF-NIP复合修饰电极,成功构建了用于检测Pb^(2+)的电化学传感器(Ho-MOF-NIP/GCE)。采用差分脉冲阳极溶出伏安法(DPASV)研究了Pb^(2+)在该修饰电极上的电化学行为。实验结果表明:该电极对Pb2的检测灵敏度显著提升,在0.1~1 mmol.LI范围内,氧化峰电流值与Pb^(2+)的浓度呈现良好的线性关系,检测限为7 pumol.L'(S/N=3),该方法可用于水样中Pb^(2+)的快速检测。

Simultaneous Voltammetric Determination of Three Herbicides in Food and Water Samples with the Aid of Chemometrics

Differential pulse stripping voltammetry method（DPSV） was applied to the determination of three herbicides, ametryn, cyanatryn, and dimethametryn. It was found that their voltammograms overlapped strongly, and it is difficult to determine these compounds individually from their mixtures. With the aid of chemometrics, classical least squares（CLS）, principal component regression（PCR） and partial least squares（PLS）, voltammogram resolution and quantitative analysis of the synthetic mixtures of the three compounds were successfully performed. The proposed method was also applied to the analysis of some real samples with satisfactory results.

基于ZIF金属有机骨架材料的重金属离子电化学传感检测

以NaOH为介导剂,利用直接搅拌法制备了Co、Zn含量不同的ZIF金属有机骨架材料,并将该材料用于重金属离子的电化学检测。利用扫描电子显微镜(SEM)、能量色散谱(EDS)、X射线衍射(XRD)、X射线光电子能谱(XPS)技术对样品的结构和形貌进行了表征,采用差分脉冲阳极溶出伏安法(DPASV)对重金属离子Pb^(2+)和Cd^(2+)进行了电化学传感检测。结果表明,所制备的ZIF金属有机骨架材料表面光滑,呈菱形十二面体形状,其尺寸随锌摩尔分数的增加而减小。Co、Zn的摩尔分数比对所构建的重金属离子电化学传感器的检测性能有很大的影响,在金属源总数为0.6 mmol的前提下,当Co、Zn摩尔分数比为1∶1.5时,电化学传感检测性能最好,对Pb^(2+)和Cd^(2+)的检测限分别达到了28.3 nmol/L和21.2 nmol/L,同时该电化学传感器也表现出较宽的线性检测范围,以及良好的稳定性、重复性和抗干扰性,可用于实际水样中Pb^(2+)和Cd^(2+)的检测。

铋纳米粒子/花状碳球电化学传感器的构建及葛根中重金属的检测研究

目的构建基于铋纳米粒子(BiNPs)/花状碳球(FCS)的电化学传感器,用于检测葛根中Cd^(2+)与Pb^(2+)的浓度。方法首先通过管式炉热裂法合成FCS;其次采用化学还原法将BiNPs负载在FCS表面;最后通过滴涂法构建电化学传感器。透射电子显微镜(TEM)和循环伏安法(CV)用于材料的表征。差分脉冲阳极溶出伏安法(DPASV)用于检测Cd^(2+)与Pb^(2+)的浓度。根据DPASV峰电流值大小对实验参数进行优化。结果在最佳实验条件下,Cd^(2+)与Pb^(2+)的峰电流响应值与浓度线性良好,R^(2)分别为0.996和0.997,线性响应范围为5~200μg·L^(-1)。Cd^(2+)与Pb^(2+)的检出限分别为0.45μg·L^(-1)和0.53μg·L^(-1)。该传感器成功用于葛根中Cd^(2+)和Pb^(2+)的检测,加样回收率在92.0%~116.8%内。结论所构建的传感器可用于葛根中Cd^(2+)与Pb^(2+)的检测。

锑原位掺杂SiO_(2)@PDA-Sb复合材料修饰电极用于海水中Zn离子检测

本研究提出了一种用于检测海水中锌离子(Zn^(2+))含量的电化学检测方法。该方法首先应用水热法合成SiO_(2)@PDA-Sb复合材料,然后将该复合材料修饰到玻碳电极上制备SiO_(2)@PDA-Sb-Nafion/GCE,利用差分脉冲阳极溶出伏安法(DPASV)对珠江口海水水样中Zn^(2+)进行测定。研究结果表明,Zn^(2+)在SiO_(2)@PDA-Sb-Nafion/GCE上具有较强的溶出峰。在最优条件下,SiO_(2)@PDA-Sb-Nafion/GCE对Zn^(2+)浓度在1~1000 nmol/L范围内可实现灵敏、准确的检测,Zn^(2+)的检测出限为0.71 nmol/L。加标回收率实验显示Zn^(2+)加标回收率为93.19%~100.12%,表明该方法可应用于现场海水样品Zn^(2+)测定。本方法具有电极制作简单、稳定性和抗干扰性良好,能够提高现有测定方法的检测限和精确度,在现场海水检测痕量Zn^(2+)具有较好的应用前景。

水环境痕量重金属检测的电化学传感器的研究

重金属是一种危险的污染物,往往长期积累在生物体内不可降解,在极其微量的情况下也会对各种生态系统产生不同程度的危害。文中采用汞膜玻碳圆盘电极,研制了一种用于监测水环境痕量重金属浓度的电化学传感器,基于差分脉冲阳极溶出伏安法(differential pulse anode stripping voltammetry,DPASV),实现了锌、镉、铅和铜4种元素的同时测定。结果表明:该传感器用于检测锌、镉、铅和铜的检出限分别为2.0μg/L、1.9μg/L、0.8μg/L和0.7μg/L.与其他重金属检测方法相比,该电化学传感器的特点是可同时快速检测多种重金属元素,传感器体积小,价格低,操作简单,灵敏度高,易于实现现场自动检测分析。

羧基化石墨烯修饰玻碳电极测定水样中的痕量铅和镉

石墨烯纳米片通过酸处理制备羧基化纳米石墨烯,将羧基化石墨烯修饰在玻碳电极表面制得石墨烯修饰玻碳电极,以此电极作工作电极,建立了微分脉冲溶出伏安法同时测定痕量铅和镉的电化学分析法。在0.1 mol/L pH 4.5的NaAc-HAc缓冲液中,在-1.2 V富集400 s后,溶出峰电流分别与Cd2＋和Pb2＋的浓度在2×10-9~2×10-7mol/L的范围内呈良好的线性关系,检测限分别为2×10-10mol/L和2×10-11mol/L。实验结果表明,玻碳电极被羧基化石墨烯修饰后检测灵敏度显著地提高。该法已用于实际水样中痕量镉和铅的测定,回收率在95%~109%之间。

同时测定癌症病人血液中锌镉铅铜的微分脉冲阳极溶出伏安法

用微分脉冲阳极溶出伏安法同时测定癌症病人血液中的锌、镉、铅和铜 ,以为癌症与这4种微量元素在血液中含量的相关性研究提供实验数据 ;癌症病人血液用硝酸 -高氯酸消化 ,消化后的白色固体加水溶解 ,以0.100mol/L硫酸铵为底液 ,在三电极体系中进行测定 ,以峰电位定性 ,峰电流定量 ;用该法测定了3种癌症病人血液中的锌、镉、铅和铜 ,相对标准偏差为2.9 %～3.3 %(n=6) ,加标回收率为98 %～110 % ;该法不用除氧、干扰少、分辨率好、准确度高 ,适用于临床血液中锌、镉、铅和铜的测定和研究。

铜膜差分脉冲阳极溶出伏安法测定药物中铋的含量

研究了铜膜电极代替汞膜电极测定重金属铋的差分脉冲溶出伏安法.实验了同位镀膜法测定铋的条件.在最佳实验条件下,Bi3+浓度在5×10-8～2×10-5mol/L范围内,其溶出峰峰高与浓度呈线性关系,检出限达到1×10-8mol/L.测定了一些药物中铋的含量,结果准确.

微分脉冲阴极溶出伏安法测定环境水样中的痕量硒

采用微分脉冲阴极溶出伏安法测定环境水样中的痕量硒,以银电极为工作电极,在酸性介质０．０６ｍｏｌ·ｌ－１ＨＣｌ－０．０７ｍｏｌ·ｌ－１ＨＮＯ３溶液中于－０．３５Ｖ(ｖｓＳＣＥ)处富集２０ｍｉｎ,使Ｓｅ(Ⅳ)电沉积为硒化银．然后,以４０ｍＶ·ｓ－１的扫速,在碱性介质２．０ｍｏｌ·ｌ－１ＮａＯＨ溶液中阴极溶出至－１．２Ｖ(ｖｓＳＣＥ),硒化银被还原为银的溶出峰峰电位约为－０．８５Ｖ(ｖｓＳＣＥ) 硒的分析校正曲线直到４０ｎｇ·ｍｌ－１仍然成线性,检测下限为１１．５ｐｇ·ｍｌ－１,相关系数为０．９９８２,灵敏度为１０．９３μＡ/ｎｇ·ｍｌ－１．２０ｎｇ·ｍｌ－１的 ＲＳＤ(ｎ＝５)为 ｌ．２６%,检出限(３σ)为 ３．４６ｐｇ·ｍｌ－１．环境水样中常见离子的存在不干扰痕量硒的测定．

活性炭吸附-差示脉冲阳极溶出伏安法测定硫酸渣提取液中痕量铊

研究了活性炭吸附-差示脉冲阳极溶出伏安法测定复杂基体（二种硫酸渣逐级提取液）中痕量铊的方法。讨论了伏安图的形成、测定底液和pH值的选择，研究了直接测定和分离测定（分离方式选择、有机物去除）的相态和方法。结果表明：炉底渣和沉灰渣的水相、粘土相和铁锰相提取液中的铊均可直接测定，炉底渣和沉灰渣有机相、碳酸盐相、硫化物相和硅酸盐相提取液中的铊用活性炭吸附分离，并用50～60℃ 50g／L的（NH4）2C2O4解吸，去除有机物后也可测定。本方法检出限为0．5μg／L，千倍浓度的9种阳离子共存或万倍浓度的8种阳离子单独存在时均不干扰。方法用于硫酸渣逐级提取液中铊的测定，结果同ICP—MS法的结果相一致。

石墨烯修饰铂电极传感器测定水中微量重金属镉和铅

建立了石墨烯修饰铂电极(G/Pt)共沉积铋膜测定水中微量重金属镉和铅的方法。采用微机电系统(MEMS)工艺制作铂电极,并利用CVD法在铂电极上原位生长石墨烯,制备了石墨烯修饰铂电极,与Ag/AgCl参比电极、铂丝对电极构成三电极体系;采用差分脉冲阳极溶出伏安法对水中微量的镉和铅进行测定。在pH=4.5的醋酸-醋酸钠(HAc-NaAc)底液中,Cd2+和Pb2+分别在#0.72和#0.48 V灵敏地产生溶出峰,线性范围分别为0.05～10 mg/L和0.03～5 mg/L,检出限均为10!g/L。本方法操作简单、安全快速、重现性好,适合于废水、地表水、及生活用水中镉和铅的测定。

纳米金-石墨烯修饰碳糊电极微分脉冲溶出伏安法检测水中铅

构建纳米金（Au）-石墨烯（GS）修饰碳糊电极（CPE）的电化学传感器（CPE│GS/Au）,建立微分脉冲溶出伏安（DPSV）法测定痕量铅的电化学分析方法。采用扫描电镜（SEM）表征GS和电极的制备过程,采用DPSV法研究铅的电化学性质。在优化的实验条件下,溶出峰电流与Pb2＋浓度在2×10-10~5×10-8g/mL范围内呈良好的线性关系,线性相关系数为0.999 0,检出限为1.2×10-10g/mL。用于实际水样分析,与石墨炉原子吸收光谱（GF-AAS）法所得结果一致,相对标准偏差（RSD）小于4.3%。该传感器采用复合纳米微粒修饰CPE,扩增了响应电流且一次使用可抛弃、分析成本低,具有较好的制备重复性。

海水重金属自动检测系统研究

基于电化学溶出伏安法研制了一种新型重金属检测系统,实现海水中锌、镉、铅、铜、锰、砷、铁和铬8种重金属元素质量浓度的自动检测.海水经过预处理后,8种重金属元素被分离为3路进入检测系统,锌、镉、铅、铜为一路,锰、砷为一路,铁、铬为一路.系统以银基汞膜电极为电化学传感器,通过PC机多线程控制三路恒电位仪电路、各蠕动泵和电磁阀,实现自动进样、检测和清洗.采用标准加入法进行定量分析,检测下限达到10-6g/L.每路只需要6 mL样品,一次测量可以在30 min内完成.系统体积小、成本低、可以连续测量,适于现场在线自动监测海水中的重金属浓度分布.

头孢噻肟钠降解产物在银微电极上示差脉冲阴极溶出伏安法的测定

基于头孢噻肟钠 (CTX)在 0 .10mol LNaOH溶液中水浴降解产物含有巯基 ( -SH) ,在pH 4 .5NaAc HAc介质中 ,于银微电极上产生一灵敏的吸附伏安还原峰 ,峰电位Ep =- 0 55V(vs.SCE)。示差脉冲溶出峰电流与CTX浓度在 1.0× 10 -7～ 1.0× 10 -5mol L范围内呈线性关系。方法可应用于模拟样品CTX的检测 ,令人满意。