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1.
徐斌  张海丽  邹欣平 《分析化学》2000,28(12):1519-1522
用线性扫描示波极谱法研究了镉(Ⅱ)-茜素紫-邻二氮菲体系的极谱行为,发现在含有0.1mol/L KCl、pH=2.85的HAc的溶液中,镉(Ⅱ)-茜素紫-邻二氮菲体系产生-灵敏的极谱吸附波,共峰电位为-0.64V(vs.SCE),峰电流与镉(Ⅱ)的浓度在5.0*10^-8-1.0*10^-6mol/L的范围内呈一性关系;检出限为3.0*10^-8mol/L。研究了电极反应机理,并用建立的方法成功地测定了废水样中的镉。  相似文献   

2.
流动注射—二极管阵列检测分光光度法同时测定铅和镉   总被引:14,自引:0,他引:14  
黎源倩  杨经国 《分析化学》1998,26(7):843-846
建立流动注射-电荷耦合器件二极管阵理分光光度法装置,研究了以meso-四(4-三甲铵苯基)卟啉为显色剂同时测定铅和镉的方法,镉和铅测定的线性范围为0~2.0mg/L和0~2.5mg/L镉的检出限为0.014mg/L,铅为0.015mg/L。进样频率为60次/h,对合成样品和陶瓷食具容器浸泡液中铅和镉进行了同时测定,获得满意的结果,样品的平均标准加入回收率为100.9%,相对标准偏差小于8.8%。  相似文献   

3.
在Triton X-100存在下,pH9.0-10.0时,新试剂苯并噻唑重氮氨基偶氮苯与镉形成3:1的橙红色络合物,最大吸收波长位于530nm,表观摩尔吸光系数为1.91×10^-5L.mol^-1;cm^-1,镉量在0-12μg/25mL范围内遵守比尔定律。在混合掩蔽剂存在下,显色反应具有良好的选择性,直接应用于工业废水中微量镉的测定,获得了满意的结果。  相似文献   

4.
示波极谱同时测定金属锌中铅和镉   总被引:2,自引:0,他引:2  
本文提出了在HCl-H_3PO_4-KCl底液中示波极谱同时测定金属锌中铅、镉含量的方法,检测下限铅为0.1mg/L,镉为0.01mg/L铅、锡波形清晰,重视性好。试样中加标准回收,铅回收率为99.2%~100%,镉回收率为95%~98%,与标准方法比较,相对误差<5%。方法准确、简便、快速,适用于金属锌中铅、镉的常规分析。  相似文献   

5.
示波极谱同时测定金属锌中铜和镉   总被引:3,自引:0,他引:3  
本文提出了在HCl-H3PO4-KCl底液中示波极谱同时测定金属锌中铅,镉含量的方法,检测下限铅为0.1mg/L,镉为0.01mg/L,铅、锡波形清晰,重现性好,试样中回标准回收,铅回收率为99.2%~100%,镉回收率为95%~98%,与标准方法比较,相对误差〈5%,方法准确,简便,快速,适用于金属锌中铅,镉的常规分析。  相似文献   

6.
以大空阻的3.三甲基硅-吡啶-2-硫酚为配体,合成了2个单核镉、锌配合物,并用X射线单晶衍射法测定了其晶体结构.  相似文献   

7.
用锌—镉测定天然水中硝酸盐的一种新方法   总被引:3,自引:2,他引:1  
提出了用锌-镉测定天然水中硝酸盐的一种新方法即通过加入NH3.H2O-NH4Cl缓冲液,使硝酸盐的还原率由20%提高到87%。方法相对标准偏差为2.1%,检出限为0.10μmol/L,回收率在95%-102%之间;与镉-铜法相比,两种方法的相对偏差小于8.2%。  相似文献   

8.
夏心泉  赵书林 《分析化学》1998,26(1):103-106
合成了新的显色试剂6-硝基-苯并噻唑重氮氨基偶氮苯,并研究了在乳化剂OP存在下马镉的显色反应。镉与试剂于pH 9.0~10.0的缓冲介质中形成稳定的红色络合物,表观摩尔吸光系数 ε526=2. 45 × 105L·mol-1·cm-1,镉浓度在0~ 0. 5 mg/L范围内符合比尔定律。该方法灵敏度高,选择性好,并用于废水和环境水样中的微量镉的测定。  相似文献   

9.
在pH5.1的HCl-六次甲基四胺缓冲溶液中,Cd(Ⅱ)-β-巯基丙酸配合物产生-灵敏的极谱吸附波.峰电流在-0.67V(vs.SCE)左右,峰高与镉浓度在1.8×10-9~3.6×10-6mol/L范围内呈线性关系.检出限为9×10-10mol/L.研究了极谱波的性质和电极过程机理.本法用于食品中痕量镉的测定,结果满意  相似文献   

10.
溶剂萃取-火焰原子吸收法测定银杏叶提取物中铅镉   总被引:10,自引:4,他引:10  
提出了用硝酸消解,KI-MIBK系统萃取,火焰原子吸收光谱法测定银杏叶提取物中痕量铅,镉的方法,铅,镉的相对标准偏差均小于4.5%,回收率分别在96.0%-100.0%和97.0%-102.0%之间。测定结果满意。  相似文献   

11.
A procedure for separation and preconcentration of trace amounts of cadmium has been proposed. A column of analcime zeolite modified with benzyldimethyltetradecylammonium chloride and loaded with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) was used for retention of cadmium. The cadmium was quantitatively retained on the column at pH approximately 9 and was recovered from column with 5 ml of 2 M nitric acid with a preconcentration factor of 140. Anodic stripping differential pulse voltammetry was used for determination of cadmium. A 0.05 ng/ml detection limit for the preconcentration of aqueous solution of cadmium was obtained. The relative standard deviation (RSD) for eight replicate determinations at the 1 microg/ml cadmium levels was 0.31% (calculated with the peak height obtained). The calibration graph using the preconcentration system was linear from 0.01 to 150 microg/ml in final solution with a correlation coefficient of 0.9997. For optimization of conditions, various parameters such as the effect of pH, flow rate, instrumental conditions and interference of number of ions, were studied in detail. This method was successfully applied for determination of cadmium in various complex samples.  相似文献   

12.
本文报道了流动注射在线柱预富集ICP光谱测定痕量金属的方法,以meso-四(4-磺基苯)卟啉为柱前衍生试剂,硅胶作固定相和盐酸作洗脱液,对痕量金属离子Cu、Mn、Ni、Fe、Pb、Cd进行在线预富集检测。在给定实验条件下,方法的富集倍数为9.3~11.3,检出限和测定的相对标准偏差(n=6)分别在0.32~26.8ng/ml和1.3%~3.0%范围内。方法用于小牛肝和西红柿叶样品分析,结果与参考值吻合。  相似文献   

13.
以大孔聚苯乙烯树脂为母体,通过-N=N-,与双硫腙键合,合成了双硫腙螯合型树脂,并将其应用于痕量铅和镉的同时分离富集,实验了酸度、流速、共存离子干扰等因素对双硫腙螯合型树脂吸附和洗脱Pb和Cd的影响,建立了双硫腙螯合型树脂同时分离富集-火焰原子吸收光度法测定食品及环境样品中痕量Pb和Cd的方法.对Pb和Cd,方法的检出限分别为0.015和0.0013μg/mL,相对标准偏差(RSD)均优于3.0%.  相似文献   

14.
研究了磷酸氢二钾对石墨炉原子吸收光谱法测定痕量镉的基体改进效应,试验表明,在磷酸盐存在下,镉的灰化温度能显著提高,钾对镉有一定的增感效应。以此建立了用磷酸氢二钾作基体改进剂,直接测定岩石、土壤和水系沉积物中痕量镉的方法。  相似文献   

15.
A simple flame atomic absorption spectrometric (FAAS) procedure for the determination of lead, bismuth, gold, palladium and cadmium as impurities in Raney nickel and nickel oxide was developed using a preconcentration step on an Amberlite XAD-16 resin packed column. Lead, bismuth, gold, palladium and cadmium were quantitatively recovered and separated from a solution containing 1 M HCl and 0.3 M NaI by the column system. Effects of the various parameters such as reagent concentrations, sample volume, matrix effects, etc. have been investigated. Under optimized conditions, the relative standard deviation of the combined method of sample treatment, preconcentration and determination with FAAS (n = 7) is generally lower than 12%. The limit of detection (3s, n = 20) was between 10–270 ng/g. The results were used for separation and preconcentration of five trace elements from nickel matrices.  相似文献   

16.
本文用单柱阳离子色谱法分离了铜、镍、锌、钻、锰、镉、铅等七种重金属离子,并首次提出用胶束增溶(增敏)络合物为柱后衍生手段。用5-Br-PADAP 为试剂,TritonX-100为增溶剂,建立了七种金属离子同时测定的离子色谱法。  相似文献   

17.
A simple flame atomic absorption spectrometric (FAAS) procedure for the determination of lead, bismuth, gold, palladium and cadmium as impurities in Raney nickel and nickel oxide was developed using a preconcentration step on an Amberlite XAD-16 resin packed column. Lead, bismuth, gold, palladium and cadmium were quantitatively recovered and separated from a solution containing 1 M HCl and 0.3 M NaI by the column system. Effects of the various parameters such as reagent concentrations, sample volume, matrix effects, etc. have been investigated. Under optimized conditions, the relative standard deviation of the combined method of sample treatment, preconcentration and determination with FAAS (n = 7) is generally lower than 12%. The limit of detection (3s, n = 20) was between 10–270 ng/g. The results were used for separation and preconcentration of five trace elements from nickel matrices. Received: 8 February 2000 / Revised: 31 March 2000 / Accepted: 7 April 2000  相似文献   

18.
Nydahl F 《Talanta》1974,21(12):1259-1267
The reduction of oxygen in aqueous solution by electrolytically precipitated cadmium, used in a reductor column, has been studied in two ways. First, by analysis of the effluent for the hydrogen peroxide formed as a reaction intermediate, the conditions for quantitative reduction have been found. Attention is called to the fact that an effluent free from hydrogen peroxide also implies quantitative reduction of all dissolved oxygen. The practical consequences are pointed out. A comparison is also made with some other reductors. Secondly, the oxidation of electrolytically precipitated cadmium by hydrogen ion is strongly inhibited, so at pH 7 it is possible to determine oxygen as the equivalent amount of cadmium ion produced in the reductor column. The conditions of quantitative reduction of oxygen are determined and found to be in agreement with those obtained by the first method. From the results the solubility of oxygen in water in equilibrium with air is estimated and found to agree with a published result considered as reliable. An outline is given of a method for determination of oxygen in aqueous solution by measurement of the amount of cadmium ions produced.  相似文献   

19.
镉的高灵敏显色体系研究及表面活性剂作用机理   总被引:7,自引:0,他引:7  
王磊  沈乃葵 《化学学报》1993,51(11):1106-1111
本文以2-氯-4-硝基苯重氮氨基偶氮苯(CNDAA)为显色剂, 研究了镉的高灵敏显色体系及表面活性剂的作用机理。研究结果表明: 对于Cd(II)-CNDAA配合物, 非离子型、阴离子型及阴-非混合型表面活性剂对此有显著的增溶增敏作用, 并以Cd(II)-CNDAA-SF显色体系建立了光度法测定微量镉的高灵敏新方法, 并对几种测定方法进行了比较, 筛选出显色条件宽容、选择性好的体系。该体系用于铝合金样品中镉的测定, 结果满意。另外, 还提出了Cd(II)-CNDAA配合物的结构, 对表面活生剂对体系的作用作了描述, 并阐明了试剂的酸性离解常数(pK~a)与显色酸度以及方法的选择性三者之间的关系。  相似文献   

20.
吴绍祖  方文焕 《分析化学》1995,23(11):1247-1251
本研究了一个高灵敏的测定镉的方法,离心光度法,该体系络合物λmax=560nm,表观摩尔吸系数ε560=5.06×10^8L.mol^-1.cm^-1,Cd^2+浓度0.10×10^-2-1.0×10^-2μg/10mL呈线性关系,本法已用于血清和水中痕量镉的测定,探讨了高灵敏的显色反应机理。  相似文献   

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