Determination of Traces of Copper,Lead, and Cadmium in Cobalt by Derivative Pulse Polarography

Abstract

A derivative pulse polarographic method is described for determining traces of copper, lead and cadmium in cobalt and its compounds without separation. In hydrochloric acid medium the detection limits are respectively about 0.02, 0.04 and 0.1 ppm in metallic cobalt when analysing 2 M cobalt solutions. The procedure was applied to the analyses of synthetic and commercially available cobalt samples and showed a satisfactory sensitivity and precision at various concentrations levels of the three impurities.     

Electrochemical Study of Lead Complexes With Folic Acid and Its Related Compounds

Abstract

The equilibria existing in unbuffered aqueous medium between lead ions and folic acid or its related derivatives (pterin, pterin-6-carboxylic acid, pteroic acid and glutamic acid) have been investigated using differential pulse polarography. All these compounds, except pterin-6-carboxylic acid and glutamic acid, exhibit three consecutive complexes with increasing ligand concen-     

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.     

Polarographic Behaviour and Determination of Kinetic Parameters of Lead-Pamoate Complex in Dimethyl Sulfoxide

The polarography of lead ion in dimethyl sulfoxide (DMSO) was investigated in the DMSO concentration range 0–80 vol.%. The complex species identified were Pb₂(DMSO)⁴⁺₃, Pb(DMSO)²⁺₃ and Pb(DMSO)²⁺₆ in [DMSO]<10 vol.%, 10< [DMSO]<43 vol.% and [DMSO]>43 vol.%, respectively. In the presence of pamoic acid, the reduction of lead ion in DMSO was two-electron reversible diffusion-controlled at pH≤6.0, but it became irreversible at pH>6.0. The complex species identified was Pb(D_m)₂(P_m)₃(OH)^6? at pH>6.0. The rate constants of electro-reduction and electro-oxidation, activation energies were determined. The hydrolysis constants of lead ion in dimethyl sulfoxide concentration 40–70 vol.% at pH 4.5–6.0 were found to be of the order of 10^?6. The stability constants of the Pb(DMSO)²⁺₃ and Pb(DMSO)²⁺₀ were also determined to be of the orders of 10¹ and 10⁵, respectively.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定硫化物矿石中的铜铅锌

建立了电感耦合等离子体原子发射光谱(ICP-AES)法同时测定硫化物矿石中Cu、Pb、Zn三种元素的方法,取代了传统的四酸(HCl+HNO3+HClO4+HF)溶样法,采用简单的盐酸和硝酸溶解矿石,大大缩短了分析时间。选择干扰少且灵敏度高的谱线作为待测元素的分析谱线,采用左右两点扣背景的方法校正光谱干扰和基体匹配方法消除物理干扰,用GBW07162和GBW07163等不同种类的国家一级标准物质进行精密度和准确度实验,测定结果的相对标准偏差都在10%以内,测定结果都在标准值的误差范围内,符合地质矿产开发的要求。     

Differential polarography of copper(II) complex

A differential polarographic study has been carried out on the interaction product formed in the interaction of copper(II) with bis(2-hydroxymethyl-5-hydroxy-4-pyrone-6)ketone. The data obtained using the differential pulse method show that copper(II) exhibits a coordination number of one and a reproducible formation constant that is fairly consistent over a moderate concentration range.     

电感耦合等离子体原子发射光谱法测定铅锌选矿流程原尾矿中铅锌铜

用5mL氟化氢铵(50g/L)、10mL盐酸、5mL硝酸、5mL高氯酸分解0.1g样品,盐酸(3%,V/V)为测定介质,定容在250mL容量瓶中,直接用电感耦合等离子体原子发射光谱法测定铅锌选矿流程原尾矿中的铅、锌、铜3种元素。根据分析线的选择原则,结合待测元素的检测范围,选择无干扰、峰形对称、灵敏度适中的谱线Pb 220.353nm、Zn 213.856nm、Cu 324.754nm作为分析线。各元素的质量浓度在一定范围内与其发射强度呈线性,校准曲线的线性相关系数均大于0.999 9,方法中各元素检出限为0.066～0.51ng/mL。方法经国家标准物质分析验证,测定值与认定值相符。按照实验方法测定铅锌选矿流程原尾矿中铅、锌、铜,测试结果与火焰原子吸收光谱法测定结果一致。     

兰州市城关区313名儿童血铅水平及其钙、铁、铜和锌的调查研究

为了解兰州市城关区儿童血铅水平及其钙、锌、铁、铜等微量元素分布状况,对兰州市城关区某幼儿园及同时期来我院儿保体检的正常儿童采耳用微量血无火焰原子吸收光谱法进行铅、钙、锌、铜、铁元素的测定。结果表明,本次调查儿童血铅≥10μg/dL者占93．9％,各年龄组间钙、锌、铜、铁有显著性差异。提示血铅水平与锌、钙存在相关关系。     

An Interlaboratory Comparison of a Standardised EDTA Extraction Procedure for the Analysis of Available Trace Elements in Two Quality Control Soils

Abstract

A standardised EDTA extraction procedure was tested collaboratively by six laboratories using two in-house reference soils identified as soil A and soil B. The extracts were analysed for Zn, Cu, Pb and Mn by Inductively Coupled Plasma Spectrometry. Concentrations of extractable elements in soil A were generally much lower than those found in soil B. All laboratories produced some extreme outlying results, most of these were produced in soil B. Results for Mn were the most variable, with a range of 63.4–100.3 μg g^?1 in soil A and 226.4–415.3 μg g^?1 in soil B. In both soils, one laboratory reported high values for Zn and Mn and, one laboratory, for soil B, produced values for all four elements which were consistently low.

If outlying results are ignored, the results from most laboratories were in reasonable agreement for all elements except Mn.     

混合酸溶-电感耦合等离子体发射光谱(ICP-OES)法同时测定多金属矿石中铜铅锌钼

为解决多金属矿石的传统分析方法中样品前处理冗长复杂、Mo的线性范围窄、不能与Cu、Pb、Zn同时测定的缺点,通过考察溶样体系、仪器工作条件、干扰及消除,建立了电感耦合等离子体发射光谱(ICP-OES)同时测定Cu、Pb、Zn、Mo四种元素的方法。结果表明,方法测定范围较宽(0.001%～20.0%),各元素校准曲线线性相关系数均在0.999 5以上,检出限为5～9μg/g。用国家标准物质进行验证,方法精密度(RSD,n=12)为0.020%～5.0%,相对误差为-4.61%～4.17%,加标回收率为88.0%～108%。实际样品的测定结果与传统方法一致,方法适合大批量、多成分分析。