阳极溶出伏安法测定地面水中铊

提出了用银基汞膜电极阳极溶出伏安法测定地面水中铊的方法。对方法的精密度,回收率及干扰离子的消除进行了试验。在０．０１６ｍｏｌ／ＬＨＡｃ－０．０２ｍｏｌ／ＬｎＡａＣＸＥＦＣＵＫＨＨＩＰ缓冲溶液和０．００６ｍｏｌ／ＬＥＤＴＡ为底液的溶液中,银     

化学需氧量光度测定法探索

试验证明,ＣＯＤ光度测定法是可行的,本法测定范围为０～２００ｍｇ／Ｌ,测定波长为４３４ｎｍ,Ｋ２Ｃｒ２Ｏ７标准溶液最佳使用浓度为０．０６７５ｍｏｌ／Ｌ（１／６Ｋ２Ｃｒ２Ｏ７）在此浓度下ＣＯＤ为２００ｍｇ／Ｌ,的葡萄糖溶液实际测得值只比标准滴定法低１．８％。     

5－Cl－PADAB－SDS分光光度法连续测定血清及废水中的铜和铁

在十二烷基硫酸钠，氟化钠和盐酸羟胺存在下，ＰＨ＝５．２～７醋酸－醋酸钠缓冲溶液中，Ｃｕ（Ⅱ），Ｆｅ（Ⅱ）分别与５－ＣＩ－ＰＡＤＡＢ形成紫红色络合物。选择测定波长为５３０ｎｍ，铜和铁的摩尔吸光系数分别为５２×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，６０×１０４Ｌ·ｍｏｌ－１·Ｃｍ－１．铜和铁分别在０～１２ｕｇ／１０ｍｌ和０～１０ｕｇ／１０ｍ１范围内符合比尔定律。选用了硫代硫酸钠－硫脲褪色液和ＥＤＴＡ掩蔽剂，直接用于血清及水中铜和铁的连续测定，结果满意。     

高压蒸汽消化法测定废水化学需氧量的再研究

用＂自控式高压蒸汽消解器＂作为高压蒸汽消化法测定废水化学需氧量的消化装置，详细研究了消化条件，最后确定，消化体系中（１／６）Ｋ２Ｃｒ２Ｏ７浓度为０１ｍｏｌ／Ｌ，Ｈ２ＳＯ４浓度为１０．１ｍｏｌ／Ｌ，催化剂Ａｇ＋浓度为０．０３ｍｏｌ／Ｌ，消化温度为１３０℃，恒温时间为２０ｍｉｎ。用此方法和条件测定了１２种单纯有机化合物和１６种不同工业废水的化学需氧量，与标准回流法相比，相对误差在－５．５－６．０％之间。     

溴甲酚绿──甲基红分光光度法测定空气中的痕量氨

本文研究了用溴甲酚绿－甲基红分光光度法测定空气中的痕量氨。在５ｍｌ吸收液中氨浓度０－２．７２μｇ／５ｍｌ遵守比尔定律。表观摩尔吸光系数ε＇６１５＝１．５５×１０４Ｌ／ｍｏｌ·ｃｍ。在采样过程中，吸收液颜色由红变绿。     

饮用水中非挥发性有机氯化物的测定

研究了一种测定饮用水中非挥发性有机氯化物（ＮＰＯＣｌ）的方法。水样经氮气气提后，以ＮａＮｏ３溶收抑制Ｃｌ－离子干扰，活性炭吸附后高温的烧，用ＮａＯＨ溶腋作吸收液，氯离子选择电极法测定并换算出ＮＰＯＣｌ值。检测限为０．２×１０~（－６）ｍｏｌ／Ｌ。在１．０×１０~（－６）～２０．０×１０~（－６）ｍｏｌ／Ｌ范围内，回收率为７５．３％。以本法测定自来水源水和末梢水，结果表明自来水厂氯化消毒引起ＮＰＯＣｌ值显著升高。建议ＮＰＯＣｌ值作为自来水水质评价的重要参数。     

废水的BOD_5测定中根据BOD_5／COD_（cr）值确定稀释比的一种方法

废水的ＢＯＤ５测定中取稀释比是一个很重要的问题。本文根据数学推导得出ＢＯＤ５测定中取稀释比的一种方法。ＢＯＤ５／ＣＯＤｃｒ值在０．０５－０．１，０．１－０．３，０．３－０．６，０．６－１．０四个范围内其稀释比ｆ２可对应取５５／ＣＯＤｃｒ、２２／ＣＯＤｃｒ、９／ＣＯＤｃｒ、５／ＣＯＤｃｒ。     

N─苯甲酰苯基羟胺／吡啶偶氮染料配体交换反应萃取分光光度法测定固体废物浸出液中的微量钒

在强酸性介质中，ＶＯ３与Ｎ－苯甲酰苯基羟胺（ＢＰＨＡ）反应生成紫红色络合物，能定量地被ＣＨＣＬ３萃取．萃取液加入２－（５－溴－２－吡啶偶氮）－５－二乙氨基酚（５—Ｂｒ—ＰＡＤＡＰ）后可发生配体交换反应，并生成橙红色的Ｖ（Ｖ）－５—Ｂｒ—ＰＡＤＡＰ络合物，有机相可直接用于光度测定．Ｖ（Ｖ）－５—Ｂｒ－ＰＡＤＡＰ的最大吸收波长为６００ｎｍ，摩尔吸光系数为５．４Ｘ１０￣４Ｌ·ｍｏｌ－１·ｃｍ－１，线性范围为０～０．７６μｇｖ／ｗｌ。     

异相平衡流动注射分光光度法测定水中痕量SO^2—4

根据异相平衡的原理,确立了用流动注射分光光度法测定水样中痕量ＳＯ＾２－４的新方法。利用Ｂａ（Ⅱ）与偶氮氯磷Ⅲ的二元络合显色反应及ＢａＳＯ４＝Ｂａ＾２＋＋ＳＯ＾２－４进入微溶化合物ＢａＳＯ４反应柱前后吸光值的改变,从而求得ＳＯ＾２－浓度。表观摩尔吸光系数ε＝２．３＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,ＳＯ＾２－４检的线性范围为０－４０ｍｇ／Ｌ,检测限为０．８０ｍｇ／Ｌ,相对标准偏差为１．２％,试     

催化动力学光度法测定痕量铜（Ⅱ）

研究了在稀硫酸介质中，用α，α‘－联吡啶作活化剂，痕量铜催化高碘酸钾氧化茂红Ｔ的褪色反应及动力学条件，建立了催化动力学光度法测定痕量铜的方法。检测限为０．４１μｇ／ＬＣｕ，线性范围为０－０．８μｇ／２５ｍＬＣｕ。方法操作简单，灵敏度高，准确性好，可用于水质及人发中痕量铜的测定，结果满意。     

Solid phase extractive preconcentration of silver from aqueous samples

N,N-dibutyl-N1-benzoylthiourea (DBBT) impregnated onto a polymeric matrix, Amberlite XAD-16 was prepared. The separation and enrichment of Ag(I) from solution was investigated. Effective extraction conditions were optimized in column methods prior to determination by atomic absorption spectrometry. The optimum pH range for quantitative adsorption is 2-5. Quantitative recovery of Ag was achieved by stripping with 1 mol L(-1) thiourea in 1 mol L(-1) HCl. The sorption capacity of resin is 0.115 mmol Ag+ g(-1) resin. The relative standard deviation and detection limit was 3.1% for 1 microg Ag+ mL(-1) solution and 0.11 microg L(-1), respectively. The method was used for the determination of silver in geological water samples.     

Seasonal variations of heavy metals in central Greenland snow deposited from 1991 to 1995

To better assess the seasonality in the fallout of heavy metals to central Greenland, a continuous series of 68 snow samples has been collected at a remote site in the Summit area from a 2.7 m pit using ultraclean sampling procedures. This covers a continuous four year time period from spring 1991 to spring 1995. Co, Cu, Zn, Mo, Rh, Pd, Ag, Cd, Sb, Pt, Pb, Bi and U were determined using ultrasensitive inductively coupled plasma sector field mass spectrometry under clean room conditions. In addition we also determined Al by graphite furnace atomic absorption spectrometry and Na+, Ca2+, SO4(2-), MSA and oxalate by ion chromatography, species that will assist in the interpretation of the trace metal data. The data show pronounced inter- and intra-annual variations, with large differences in the amplitude of these variations for the element studied, with few clear seasonality patterns. Generally, high concentrations are observed in the spring snow layers, while much lower concentrations are typical of summer snow layers. Significant correlations are observed between Co, Cu, Zn, Ag and Sb, while Pt, Pd and Rh show no correlation with the other metals. Crustal enrichment factors show that while the crustal dust contribution is probably important for some metals for part of the year (spring), anthropogenic inputs are as important in many instances. Pronounced intra-annual variations are observed for some metals, in particular Pt. The variations observed for this metal parallel fairly closely changes in Russian Pt production, which points to emissions from smelters in the Russian Arctic as likely sources for Pt.     

The effects of anthropogenic particulate emissions on roadway dust and Nerium oleander leaves in Messina (Sicily, Italy)

Complementary studies on the inorganic chemical composition of Nerium oleander leaves collected in the town of Messina (Sicily, Italy) and seven grain-size fractions of local roadway dust have been carried out. Data and maps are presented to show that the particulate matter present in the air of Messina contains trace elements significantly in excess with respect to the average continental earth crust. The anomalies follow the outline of the urban area, the highest concentrations of trace elements being observed where traffic density is highest. Chemical and isotopic analyses of both road dust and Nerium oleander leaves indicate that Pb contamination still characterizes roads with heavy traffic. In addition to Pb, other metals such as Pt, Pd, Sb, Au, Br, Zn, Cu, Mo, and Cd are significantly enriched in roadway dust, indicating their common anthropogenic origin, especially from traffic. SEM/EDS study of some roadway dust particles has shown the presence of gypsum probably of secondary origin, mixed particles formed by coagulation or gas-to-particle conversion, and porous spherical particles apparently emanating from combustion processes.     

First study on anthropogenic Pt, Pd, and Rh levels in soils from major avenues of S?o Paulo City, Brazil

Over the last years, investigations on the increase of platinum (Pt), palladium (Pd), and rhodium (Rh) levels in urban environments of big cities all over the world - especially to catalytic converters emissions - have been grown up enormously. S?o Paulo City is the 6th largest megacity in the world having about 20 million inhabitants and an ever increasing seven million motor vehicle fleet. In spite of this, there has never been an investigation regarding Pt, Pd, and Rh levels in the city. In the present study, Pt, Pd, and Rh concentrations were determined in soils adjacent to seven main high-density traffic avenues in the metropolitan region of S?o Paulo City. Inductively coupled plasma mass spectrometry was employed - after ultrasound-assisted aqua regia leaching - as analytical technigue. The results showed concentration levels up to 378?ng?g^?1 for Pd, 208?ng?g^?1 for Pt, and 0.2 to 45?ng?g^?1 for Rh. These levels are much higher than those considered for the geochemical background of soils, indicating a catalytic converter source. Due to the different Pt/Pd/Rh ratio in Brazilian automobile catalytic converters, lower levels of Pt/Pd ratios compared with other similar studies were observed. The obtained results are the first data for monitoring Pt, Pd, and Rh pollution in S?o Paulo City soils.     

Speciation of Trace Metals in Coastal Sediments of El-Mex Bay South Mediterranean Sea–West of Alexandria (Egypt)

Sediments of El-Mex Bay estuary on the southern Mediterranean Sea have been analyzed for trace metals after sediment fractionation by sequential leaching. A sequential extraction procedure was applied to identify forms of Mn, Cu, Cd, Cr, Zn and Fe. The five steps of the sequential extraction procedure partitioned metals into: CH₃COONH₄ extractable (F1); NaOAC carbonate extractable (F2); NH₂OH.HCl/CH₃COOH reducible extractable (F3); H₂O₂–HNO₃ organic extractable (F4) and NHO₃/HClO₄/HF acid soluble residue (F5). Extracted concentrations of trace metals analyzed after all five steps, were found to be (μg/g) for Mn: 1930.2, Cu: 165.3, Cd: 60.9, Cr: 386.3, Zn: 2351.3 and Fe: 10895. Most of elements were found in reducible fraction except Fe found in acid soluble residue, characterizing stable compounds in sediments. Labile (non-residual) fractions of trace elements (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis was used to understand and visualize the associations between the labile fractions of trace metals and certain forms, since Fe-and Mn-oxides play an important role in trace metals sorption within aquatic systems, especially within El-Mex Bay sediments that characterized by varying metal bioavailability.     

Preconcentration of Zn2+ and Cu2+ ions from food and vegetable samples using modified activated carbon

In this work, two N/S-containing chelating agents 2-(4-methoxybenzylideneamino)thiophenol (2-4-MBAT) and 2-(4-chlorobenzylideneamino) benzenethiol (2-4-CBABT) were synthesized as new sorbents and were used for preconcentration of Zn(2+) and Cu(2+) ions in food and vegetable samples. In the proposed procedure, the trace amount of Zn(2+) and Cu(2+) ions from 250?mL of sample solution at pH?=?5.0 was preconcentrated by 1?g of activated carbon (AC) loaded with 15?mg of 2-4-MBAT and 2-4-CBABT separately. The breakthrough volumes (maximum sample volume that their metal ions quantitatively can be enriched) for solid-phase extraction (SPE) procedure based on the AC modified with 2-4-MBAT and 2-4-CBABT were 800 and 750?mL, respectively. The sorbed Zn(2+) and Cu(2+) ions were efficiently eluted by 8?mL of 4?mol?L(-1) HNO(3) and preconcentration factor of 112.5 and 93.7 and experimental enhancement factor of 30 and 35 ions were obtained for Zn(2+) and Cu(2+), respectively. The application of this enrichment procedure allowed the extraction of trace metal ions with recoveries exceeding of 90%.     

Predatory aquatic beetles, suitable trace elements bioindicators

Predatory aquatic beetles are common colonizers of natural and managed aquatic environments. While as important components of the aquatic food webs they are prone to accumulate trace elements, they have been largely neglected from metal uptake studies. We aim to test the suitability of three dytiscid species, i.e.Hydroglyphus pusillus, Laccophilus minutus and Rhantus suturalis, as trace elements (Al, As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se and Zn) bioindicators. The work was carried out in a case area representing rice paddies and control sites (reservoirs) from an arid region known for its land degradation (Monegros, NE Spain). Categorical principal component analysis (CATPCA) was tested as a nonlinear approach to identify significant relationships between metals, species and habitat conditions so as to examine the ability of these species to reflect differences in metal uptake. Except Se and As, the average concentrations of all other elements in the beetles were higher in the rice fields than in the control habitats. The CATPCA determined that H. pusillus had high capacity to accumulate Fe, Ni and Mn regardless of the habitat type, and hence may not be capable of distinguishing habitat conditions with regards to these metals. On the other hand, L. minutus was found less sensitive for Se in non-managed habitats (i.e. reservoirs), while R. suturalis was good in accumulating Al, Mo and Pb in rice fields. The latter seems to be a promising bioindicator of metal enrichment in rice fields. We conclude that predatory aquatic beetles are good candidates for trace elements bioindication in impacted and non-impacted environments and can be used in environmental monitoring studies. CATPCA proved to be a reliable approach to unveil trends in metal accumulation in aquatic invertebrates according to their habitat status.     

The impact of vehicular fallout on the Pra estuary of Ghana (a case study of the impact of platinum group metals (PGMs) on the marine ecosystem)

It is increasingly being recognised and environmental measurements have demonstrated that Platinum (Pt) (and potentially Rhodium (Rh) and Palladium (Pd)) is released with the ageing of catalytic converters. Platinum is a particular concern as it has a known mutagenic and toxic effect, even at exceedingly low concentrations, in urban air (affecting human health) and urban water (affecting ecosystem health). In the context given above and given the still keen lack of reliable experimental data on the levels of Pd, Pt and Rh in water and sediment, this study determined the concentration of such elements in water and sediment of the Pra estuary in the Western Region of Ghana where it is estimated that more than two thousand cars pass over the bridge under which the river flows to join the sea each day. Elevated concentrations of platinum (Pt), palladium (Pd) and Rhodium (Rh) were found to be associated with water and soils from areas of high traffic densities (Beposo) suggesting that vehicles also contribute heavy metals (PGMs) to the environment. The result showed elevated levels of these metals in river bank, waterbed and in the water. There is therefore the tendency of possible accumulation of these metals in plant and animals along these areas.     

Contribution to biomonitoring of some trace metals by deciduous tree leaves in urban areas

Leaves of the deciduous tree species, horse chestnut (Aesculus hippocastanum L.) and Turkish hazel (Corylus colurna L.) were used as accumulative biomonitors of trace metal pollution in the urban area of Belgrade. Using differential pulse anodic stripping voltametry, trace metal concentrations (Pb, Cu, Zn, Cd) were determined at the single leaf level (ten leaves per species, per month), during two successive years with markedly different atmospheric level of trace metals. Increased trace metal concentrations in the leaves of A. hippocastanum reflected elevated atmospheric trace metal pollution, whereas C. colurna L. did not respond accordingly. The contents of Pb and Zn in soil over the same period also followed this trend. Anatomical analyses, in young as well as in old leaves of both species, indicated typical foliar injuries of plants exposed to stressful air conditions. Water relations that correspond to leaf age may have contributed to the considerable trace metal accumulation in leaves.     

土壤和底质中砷形态分析前处理技术

利用可溶性砷（包括有机砷、砷的无机含氧化合物）和硫化砷的特性进行砷的形态分析。在２ｍｏｌ／Ｌ盐酸中提取可溶性砷,与硫化砷进行分离,分别测定总砷和可溶性砷后差值为硫化砷,在９ｍｏｌ／Ｌ硫酸－碘化钾溶液中用苯萃取砷的无机含氧化合物与有机砷进行分离,可分别测定有机砷的砷的无机含氧化合物。