HPLC-ICP-MS快速、准确测定鱼肉组织中的砷甜菜碱(AsB)

采用高效液相色谱与电感耦合等离子体质谱法联用测定鱼肉样品中的砷甜菜碱,样品前处理采用快速溶剂萃取,分析方法快速、准确。通过测定鱼肉中砷甜菜碱的标准参考物质以及在欧洲实验室间对盲样进行比对实验,进一步验证了该方法的有效性。采用等度洗脱一次可分离分析多达6种不同形态的砷,仅需10分钟。通过优化方法,最大程度地简化了费时的样品前处理步骤并实现了对大批量样品进行自动萃取与分析。该实验分别比较了标准加入法与外标法的测定结果,结果显示两者并无显著差异,表明HPLC＿ICP＿MS法受基体影响极小。萃取过程中可自动处理多达24个样品,所建立的HPLC＿ICP＿MS分析方法稳定、可靠,能连续进样50针以上,相当于总运行时间在12小时以上。因此,该方法适用于毒物甄别研究中快速、准确地判断砷总含量较高的鱼肉样品中无毒砷甜菜碱的比例。     

Criteria for the evaluation of dioxins in the environment

In FRG and other countries unequivocal criteria for the limitation of dioxins (PCDD's/PCDF's) in food like vegetables and fruits are lacking. These have to be directly associated with the limitation of dioxins in the soil and the deposition of particulate matter as the two main pathways for plant contamination. Based on recent investigations in the vicinity of cable-waste incinerators in Northrhine-Westphalia with comparatively high contents of dioxins in garden plants and soils and other sources of dioxins, considerations are given for the establishment of the criteria urgently needed.     

Vertical profile of PCDD/Fs, dioxin-like PCBs, other PCBs, PAHs, chlorobenzenes, DDX, HCHs, organotin compounds and chlorinated ethers in dated sediment/soil cores from flood-plains of the river Elbe, Germany

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and other organic micropollutants were determined in dated sediment/soil cores collected from the flood-plain of the river Elbe near Pevestorf (PT), approximately 125 km upstream of Hamburg, and Heuckenlock (HL) in southeast of Hamburg. Concentrations of PCDD/Fs peaked sharply at PT in the 1950s and at HL at the end of the 1940s. Cluster analyses provide evidence that the region of Bitterfeld-Wolfen (about 350-400 km upstream of Hamburg) could be the source of the PCDD/F contamination existing in the cores PT and HL since the 1940s. Obviously it is caused by sediments of the river Elbe of a similar composition. Whereas the PCDD/Fs, HCHs (hexacyclohexane isomers), DDX (DDT, DDD, DDE), and tetrachlorinated ethers in PT and HL presumably originated predominantly from the Bitterfeld-Wolfen region, organotin compounds in HL and dichlorinated haloethers in HL during the 1940s and 1950s can probably largely be attributed to emissions from the Hamburg region. Although they are separated by a large distance, in both sediment cores PT and HL concentrations and composition patterns of most organic micropollutants analyzed widely match. Inductively it can be concluded that similar contaminations will be found in many of the river bank soils between the Bitterfeld-Wolfen region and Hamburg. Excavation of top soils may uncover highly contaminated materials. Since the dated sediment cores show the variation in contaminants in the Elbe sediments over a defined time period, it is possible to make an approximate assessment of the actual degree of contamination to be expected in areas where in previous decades contaminated dredged sediments from the Elbe and from the Port of Hamburg have been deposited on land and used for building plots or for agricultural purposes.     

Homologue distribution patterns of 2,3,7,8-chloro-substituted PCDD/F in Bavarian soils

Background

Soil-background values of PCDD/F concentrations are usually conveniently displayed as toxic equivalent (TEq), being a bulk parameter of all relevant 7 PCDD- and 10 PCDF-congeneres, chloro-subsidized at the 2nd, 3rd, 7th and 8th carbon atom. Data here are ample, not so survey on congenere/homologue patterns occurring in soils. The sufficient number of samples taken within this analysis allowed first a well-grounded evaluation.

Results

OCDD proved to be the dominant congenere in all samples (forest and agriculture), however, in considerably different concentrations. As expected, highest level was detected in forest organic layers, followed by forest top soils, cropland- and grassland top soils. Although highest in concentration, OCDD only contributes to 0.17% (both forest organic- and top soil layer), respectively, 0.4% (cropland) and 0.3% (grassland) to TEq. The influence of lower chlorinated homologues on TEq is strongest in forest top soils (72%) followed by 67% (forest organic layers), cropland top soil (63%) and grassland (61%). Although all homologue patterns (forest and agriculture) give a fairly similar picture, a test of significance (χ ²) proved a different population of forest samples.

Conclusions

The resemblance of the homologue patterns throughout all utilization suggests that agent levels are explained mainly by diffuse atmospheric depositions rather than by specific land use input.

     

Drivers for the use of materials across countries

This paper analyses drivers for resource use and material productivity across countries. This is not only relevant in light of soaring raw material prices but also because EU policies, such as the ‘Thematic Strategy on the Sustainable Use of Natural Resources’ (COM [2005] 670), the EU Raw Materials Initiative (COM [2008] 699) and various similar policies internationally, seek to better manage materials along their life-cycle and across economies. In order to better understand the system dynamics of material use, our paper applies methodologies of material flow analysis and regression analysis to identify the major drivers for resource use and decoupling from GDP. Drivers are understood as those factors that exert influence on human activities to use resources. A panel data set is taken for the European Union for the years 1980-2000 (EU-15) and 1992-2000 (EU-25). The main drivers of resource use were found to be energy efficiency, new dwellings and roads construction activities. Shortcomings of the methodology are also discussed.