The effect of inorganic particulates on the ASV signals of Cd, Pb and Cu

The potential influence of inorganic particulates on the ASV response of < 100-microg/l. levels of Cd, Pb and Cu, at a thin film mercury electrode, was examined by adding various weights of the solids to the acetate background electrolyte solution. Materials added included the hydrous oxides of Mn(IV), FE(III) or Al(III), clay minerals (kaolinite, illite, montmorillonite) and some contaminated sediments. Abrasion of the mercury film was minimized by deaerating the turbid solutions before their transfer to the measuring cell. The hydrous oxides specifically sorbed all three metal ions, resulting in peak-size changes that varied in magnitude with pH. With the clays, only sorption of Pb by illite or montmorillonite was detected. The presence of the solids had little effect on the peak position or half-peak breadth of the Cd or Pb signals, but the Cu peak parameters changed, indicating some hydroxy-species formation at higher pH. Some contaminated sediment samples released a significant fraction of their total metal content into acetate buffer solutions. Shielding the mercury film with a semipermeable membrane had a similar effect to filtering the suspension before analysis, but diffusion equilibrium was only slowly achieved (> 12 hr).     

The influence of pH and complex formation on the ASV peaks of Pb, Cu and Cd

The effects of pH, electrolyte composition and complex formation on the size and position of the ASV peaks of Pb, Cu and Cd have been systematically evaluated, with an instrument equipped with a mercury thin-film electrode and by applying a linear ramp voltage scan. The peak heights change with pH and the magnitude of the pH effect varies with base electrolyte composition. Anions such as chloride and acetate reduce the signal, as does the presence of excess of ligands such as 2,2'-bipyridyl, NTA and EDTA. Formation of stable chelates (e.g., with EDTA) can lead to total loss of signal, but dissociation of labile complexes can be enhanced by reducing the pH and/or increasing the magnitude of the applied deposition potential, thus producing measurable peaks. The peak potentials vary with pH, and in copper systems there are additional shifts in the presence of citrate, 2,2'-bipyridyl and chloride. With the last two, double peaks are formed and these are attributed to the formation of both Cu(I) and Cu(II) oxidation products. The varied response, particularly in the case of copper, which can follow changes in the base electrolyte composition, supports the need for careful control of the chemical environment in quantitative determination, and raises some queries about the feasibility of using direct ASV for speciation purposes.     

电感耦合等离子体质谱法测定海洋贝类中镉、铬、铜和铅

采用微波消解法处理海洋贝类样品,用电感耦合等离子体质谱法测定样品中镉、铬、铜和铅等4种重金属元素的含量。选择111 Cd、53 Cr、63 Cu和208 Pb等待测元素的同位素克服了质谱干扰。4种元素分别在一定的质量浓度范围内呈线性,检出限(3s)在0.005～0.17μg.L-1之间。镉、铬、铜和铅的回收率分别为94.7%,102.1%,101.9%,105.3%;测定值的相对标准偏差(n=7)分别为4.3%,3.8%,1.5%,6.0%。     

火焰原子吸收光谱法测定蚯蚓中铜、锌、镉和铅

随着工业生产的发展和人们生活水平的不断提高,城市垃圾处理场的重金属含量越来越高。部分重金属通过大气和水进入土壤,由于污染给生物和人类带来危害。大型土壤动物-蚯蚓,是土壤污染中敏感的指示动物,受到国内外学者的重视。因此,通过对蚯蚓的监测来评价土壤的污染程度是常用的方法之一。本法将蚯蚓洗净泥沙,置黑暗处饥饿养殖3天,待其基本排尽粪便,经烘干研磨制成粉,经硝酸-高氯酸消解后,用火焰原子吸收光谱法测定其中的铜锌镉铅含量。方法简便、快速,相对标准偏差为0．5％～3．7％,加标回收率为94．0％～106．0％,获得满意的结果。     

石墨炉原子吸收光谱法测定水中镉铜铅的在线富集预处理

将流动注射在线预富集系统与石墨炉原子吸收光谱法联用 ,以C18 反相键合硅胶为柱材料,5 -磺基-8 -羟基喹啉为螯合剂 ,2mol/LHCl-0.1mol/LHNO3 为洗脱液 ,以固定体积方式测定了Cd、Cu和Pb ,富集倍数分别为22、28、26(与30μL进样量相比 ) ,检出限(3σ)分别为0.7ng/L、4.2ng/L、5.4ng/L。     

Behavior of Zn,Cu, Pb and Cd in biota of Yangtze Estuary

The contents of zinc, copper, lead and cadmium were measured in the dominant species (plants:Scripus triquetor andPhrgrmites australis, macrobenthos:Ilyoplax deschampsin, Helice tridens tientsinensis, Bullacta exarata and Corbicula fluminea, and migrating waders: Calidris ruficollis and C. alpina) of the ecosystem of Yangtze Estuary, China, from 1995–1998. Results show that:

1. (1)

   Since the heavy metals stored in plants during growth seasons will be released into the environment in winter, plants are temporary stocks for metals. For the aboveground parts of reeds, about 156.6 kg·ha^-1·a^-1 of zinc, 369.9 kg·ha^-1·a^-10 of copper, 32.9 kg·ha^-·a^-1 of lead and 6.5 kg·ha^-1·a^-1 of cadmium were released.

2. (2)

   The mollusca, especially C.fluminea, are the key species storing and transporting heavy metals on the food chain.

3. (3)

   The temporal change in the highest trophic level was studied and found that it was significantly related with metabolic rates. The contents of heavy metals in Dunlin reach the peaks in January and October, which are wintering season and migratory season, respectively, of the bird.

4. (4)

   Organisms often show regulation/accumulation mechanisms to different elements of heavy metals. The elements that are widely required, such as zinc and copper, are accumulated at the metabolically active parts. It is quite another thing for the other two elements. Lead was regulated well and scarcely accumulated in the bodies of macrobenthos, but cadmium was absolutely accumulated in the animals.

5. (5)

   Heavy metals were found accumulated in some parts of the bodies of these organisms, such as shells and skeletons of macrobenthos and lives and muscles of waders.

6. (6)

   All these four elements were accumulated higher in the bodies of waders than in the plants and macrobenthos, which showed a bio-magnification function of the food chain. Overall, besides the physical and chemical processes, biological processes of heavy metal elements in Yangtze Estuarine ecosystem play a very important role in self-purification function of the ecosystem. Measurement of heavy metal contents in plants and animals in the estuarine ecosystem is an efficient technology for monitoring the environmental quality of the estuary.

     

Behavior of Zn, Cu, Pb and Cd in biota of Yangtze Estuary

The contents of zinc, copper, lead and cadmium were measured in the dominant species (plants: Scripus triquetor and Phrgrmites australis, macrobenthos: llyoplax deschampsin, Helice tridens tientsinensis, Bullacta exarata and Corbicula fluminea, and migrating waders: Calidris ruficollis and C. alpina) of the ecosystem of Yangtze Estuary, China, from 1995-1998. Results show that:     

石墨炉原子吸收法测定香根草中痕量Pb、Cd、Cu

采用石墨炉原子吸收法直接测定了香根草中重金属的含量,通过一系列实验,确定了石墨炉法测定Pb、Cd、Cu的最佳灰化温度和原子化温度,考察了精密度和回收率。结果表明,该法操作简单快捷,样品用量少,灵敏度高,稳定性好。     

Simultaneous determination of Cu, Cd and Pb in drinking-water using W-Coil AAS

An inexpensive, multi-element, W-coil atomic absorption spectrometer has been developed. Atomization occurs on W-coils extracted from commercially available slide projector bulbs. The system has minimal power requirements, 120 ACV and 15 A. A small, computer controlled CCD spectrometer is used as the detector. A multi-element Cu, Cd and Pb hollow cathode lamp is used as the source. 20 mul volumes are deposited on the coil and atomized at 6.7 A or approximately 2200 degrees C. Cu, Cd and Pb were simultaneously determined in tap water, drinking water and a quality control sample. The instrument detection limits are 0.8, 0.2 and 3.0 mug/l for Cu, Cd and Pb, respectively.     

Polarographic determination of Cu, Cd, Pb, Bi and Tl in succinic acid

Summary Copper, cadmium, lead, bismuth, and thallium develop well defined polarograms in 0.1 M succinic acid at pH 3.0 in presence of 0.005% gelatin (except Cu which requires 0.01% gelatin). The polarograms of all these metal ions are diffusion controlled with E _1/2 at –0.07 V, –0.60 V, –0.43 V, –0.11 V, and –0.50 V vs. S.C.E., respectively. Since the half wave potentials of some of the metal ions are well separated, their simultaneous polarographic determination is possible (Cu/Pb, Bi/Pb, Pb/Zn, Cu/Cd).

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Polarographische Bestimmung von Cu, Cd, Pb, Bi und Tl in Bernsteinsäurelösung

Zusammenfassung Die genannten Metalle liefern gut ausgebildete diffusionskontrollierte Polarogramme in 0,1 M Bernsteinsäurelösung bei pH 3,0 in Gegenwart von 0,005% Gelatine (0,01% bei Cu). Die Halbstufenpotentiale betragen: –0,07 V, –0,60 V, –0,43 V, –0,11 V bzw. –0,50 V (gegen GKE). Da sie teilweise gut voneinander getrennt sind, können Bestimmungen dieser Metalle nebeneinander ausgeführt werden (Cu/Pb, Bi/Pb, Pb/Zn, Cu/Cd).

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Our sincere thanks are due to Dr. G. B. Singh, Professor and Head, Dept. of Chemistry, B. H. U., for providing the necessary facilities.     

火焰原子吸收法连续测定茶叶中铅、铜、锌、镉含量

采用火焰原子吸收方法连续测定了茶叶中铜，铜，锌，镉的含量，方法灵敏，准确。测定时无需富集，萃取，操作简便，回收率93．0％－98．1％，相对标准偏差不超过5．3％。     

Das Verhalten von Cd, Pb und Cu in Phosphors?ure

Ohne Zusammenfassung     

电感耦合等离子体质谱法测定铅锌矿尾矿渣中铜、铅、锌和镉

采用硝酸-氢氟酸-高氯酸溶解样品,用电感耦合等离子体质谱法测定了铅锌矿尾矿渣中的铜、铅、锌和镉。以铑为内标元素,选择63 Cu,66Zn,208 Pb,114 Cd作为测量同位素。铜、铅、锌的线性范围为200μg·L-1,镉的线性范围为1.0μg·L-1,检出限(3s)分别为0.04,0.10,0.03,0.003μg·g-1。测定值的相对标准偏差(n=11)在0.39%~2.2%之间。用此方法分析标准物质,测定值与认定值相符。     

火焰原子吸收分光光度法直接测定水中微量铜、铅、锌、镉

将水样浓缩10倍处理,用空气-乙炔火焰原子吸收分光光度法直接测定水中微量铜、铅、锌、镉元素的含量,在0～1.00 mg/L范围内,被测元素浓度与吸光度呈线性关系,相关系数不小于0.9990.最低检出限分别为0.001、0.01、0.0008、0.0005 mg/L,相对标准偏差分别为1.16%、1.22%、1.15%、1.16%.该方法对标准样品的测试结果与国家标准方法基本一致,相对偏差均不大于7.0%.     

Decomposition of vegetables for determination of Zn,Cd, Pb and Cu by stripping voltammetry

A simple and accurate digestion method using nitric acid, perchloric acid and hydrogen peroxide has been developed for use in trace analysis for heavy metals in vegetables by differential pulse anodic stripping voltammetry. The recovery of the metals from the samples is lower if the hydrogen peroxide is omitted from the digestion mixture. Standard reference materials have been analysed satisfactorily by this method.     

Road dust pollution of Cd, Cu, Ni, Pb and Zn along Islamabad Expressway, Pakistan

Islamabad Expressway is one of the busiest roads in the capital of Pakistan. For the assessment of heavy metal pollution level in dust generated on the Expressway, 13 samples of dust were collected from various places around the highway and four samples of soil were obtained from the undisturbed green land in Islamabad. The samples were analyzed for five heavy metals using FAAS (flame atomic absorption spectrometry). The average concentration values of the metals Cd, Cu, Ni, Pb and Zn were found to be 5 ± 1, 52 ± 18, 23 ± 6, 104 ± 29 and 116 ± 35 mg kg^{- 1} respectively, which were generally lower than the values cited in literature. The inter-elemental correlation of Cu and Pb indicated that they belonged to common anthropogenic sources. The pollution level was estimated based on the geoaccumulation index (I_geo), the pollution index (PI), and the integrated pollution index (IPI). The values of IPI were in the following order: Cu > Pb > Zn > Cd > Ni. All the indices for the metals under consideration were either low or corresponded to middle level of pollution. The pollution level is expected to increase due to rapid urbanization of the area. Some protective measures have therefore been proposed.     

用反相高效液相色谱法分析测定Cd,Hg,Pb和Cu

用直接进样（Ｃ１８柱）反相高效液相色谱法研究了Ｍｅｎ＋－Ｄｚ（二硫腙）体系的色谱行为,建立了同时测定Ｃｄ,Ｈｇ,Ｐｂ和Ｃｕ的分析方法。方法的线性范围为０．０１～２．０ｍｇ／Ｌ,最低检出质量浓度为２．４～５．０μｇ／Ｌ,相对标准偏差为１．８％～９．７％,回收率为９４％～１０３％（Ｈｇ除外）。直接进样反相高效液相色谱法比萃取进样正相液相色谱法更快速,更简便,更容易操作,已用于人发测定。     

微波消解-原子吸收光谱法测定酵母中铁、铜、锰、铅、镉

采用微波消解-原子吸收光谱法测定了高活性干酵母中铁、铜、锰、铅及镉5种微量元素含量。用微波消解法处理样品,具有简便、快速的优点。方法的标准曲线线性关系良好(r=0.995~0.999),方法加标回收率在96.0%~103.0%,相对标准偏差(RSD,n=6)在2.0%~4.9%。表明方法具有较好的准确性和重复性,用于实际酵母样品的测定,获得了满意的结果。     

Voltammetric method for the determination of Zn, Cd, Pb, Cu and Ni in interstitial water

To determine heavy metals in interstitial water from Baltic sea sediments a sampling method with subsequent voltammetric determination is described. Copper, lead, zinc and cadmium are determined in the UV-digested samples of interstitial water by differential pulse anodic stripping voltammetry while nickel is determined by adsorption voltammetry. The determination of five metals in one sample in a wide concentrations range is possible using a low cost apparatus. The profiles of the metal concentrations in interstitial water of subsequent layers of sediments, sampled from Puck Bay, Gdask Bay, the Bornholm area and the Supsk area are presented.