原位显微红外法检测热胁迫对荒漠植物刺叶墙藓质膜透性的影响

利用显微红外光谱法研究了不同生境下的刺叶墙藓质膜结构及其热胁迫耐性机理。从酯酰基、碳氢化合物红外吸收区域分析表明,刺叶墙藓野生叶片通过加快组织内部碳氢化合物合成速度,减少质膜渗透性,减轻高温对质膜胁迫损伤;室内培养的原丝体和新叶不能及时对热胁迫产生影响。     

Multi-element atmospheric deposition study in Croatia

For the first time the moss biomonitoring technique and two complementary analytical techniques ? neutron activation analyses (NAA) and atomic absorption spectrometry (AAS) ? were applied to study multi-element atmospheric deposition in the Republic of Croatia. Moss samples were collected during the summer of 2006 from 98 sites evenly distributed over the country. Sampling was performed in accordance with the LRTAP Convention?-?ICP Vegetation protocol and sampling strategy of the European Programme on Biomonitoring of Heavy Metal Atmospheric Deposition. Conventional and epithermal NAA and AAS made it possible to determine concentrations of 41 elements including key toxic metals such as Pb, Cd, Hg, and Cu. Factor analysis (Principal component analysis with varimax rotation) was applied to distinguish elements mainly of anthropogenic origin from those predominantly originating from natural sources. Geographical distribution maps of the elements over the sampled territory were constructed using GIS technology. For the elements included in the European programme, the median values for Croatia were generally around the average median values observed in Europe. The Adriatic coastline of Croatia may be considered as an environmentally pristine area. This study was conducted in order to provide a reliable assessment of air quality throughout Croatia and to produce information needed for better identification of pollution sources and improving the potential for assessing environmental and health risks in Croatia associated with toxic metals.     

Biomass-modified carbon paste electrodes for monitoring dissolved metal ions

Electrodes were prepared by incorporating dried, nonliving biomass of a common lichen, Ramalina stenospora, and Sphagnum (peat) moss in carbon paste. The electrodes were tested on solutions containing Pb(II) and Cu(II) ions by immersing the electrode in the solution for selected periods of time to accumulate ions. Following this the electrode was connected to a potentiostat and the applied voltage scanned from −1.0 to +0.5 V vs. SCE. Any adsorbed metal ions were stripped back into solution at the appropriate oxidizing voltage. The ratio of biomass to mineral oil to graphite has been found to be crucial to electrode performance. Different ratios of the three components using the lichen Ramalina stenospora were evaluated for maximum electrode performance. Only two electrode compositions gave a good electrode response for lead. Electrodes containing peat moss were superior in performance to lichen-containing electrodes for lead. Electrodes based on the lichens Cladina evansii and Letharia vulpina, the marine algae Ulva lactuca and Sargassum fluitans, the blue-green alga Spirulina platensis, and the aquatic plant Eichhornia crassipes did not respond to lead at all. All functioning electrodes studies showed a poor response toward copper(II) ions.     

Characterization of Heavy Metal Air Pollution in Romania Using Moss Biomonitoring,Neutron Activation Analysis,and Atomic Absorption Spectrometry

ABSTRACT

Heavy metal air pollution in Romania was investigated by using passive moss biomonitoring. This study is a component of an international UNECE ICP Vegetation Program – moss survey. A total of 330 samples of Hypnum cupressiforme, Hylocomium splendens, Pleurozium schreberi, and other mosses were collected in Romania in the summer and autumn of 2010. The concentrations of aluminum, cadmium, chromium, copper, iron, lead, nickel, vanadium, and zinc were determined by graphite furnace/flame atomic absorption spectrometry and instrumental neutron activation analysis. The results were statistically processed to obtain spatial distribution maps of factor scores based on elemental concentrations in the moss, together with the spatial distribution maps of heavy metals in moss. The median concentrations of cadmium, 1.20?mg/kg dry weight, and lead, 30.8?mg/kg dry weight, were high compared with other European countries. The results revealed that the atmospheric deposition of these metals is a problem in north and northwest Romania.