荆州大气氟污染与植物叶片含氟量监测分析

本研究对荆州市区内的多种植物叶片含氟量进行了测定 ,同步测定了大气的氟污染状况 ,并进行了相关性分析。结果表明 ,荆州市部分区域存在一定程度氟污染 ,不同区域及不同植物叶片含氟量有明显的差异 ,叶片氟累积量与大气中氟含量呈显著的正相关。     

超声辅助乳化液相微萃取分析绿茶饮料和番茄汁中有机磷农药残留

农药施用于田间,必然会残留于环境中。农药残留的分析方法多种多样。为探究灵敏度高、重现性好的样品前处理方法,建立了超声辅助乳化液相微萃取,结合气相色谱和火焰光度检测器测定绿茶饮料和番茄汁中5种有机磷农药的方法,对萃取条件进行了优化,如萃取溶剂种类和体积、超声频率和时间、盐效应。在优化后的萃取条件下,5种有机磷农药实现良好分离,空白添加实验结果表明在0.1~10μg·L-1之间,线性相关系数在0.9985~0.9994之间,检测限在0.005~0.020μg·L-1之间,相对标准偏差(n=5)在4.3%~9.4%之间。在绿茶饮料和番茄汁实际样本检测中,目标分析物含量均低于检出限。样本添加回收试验的回收率均大于88.5%,相对标准偏差(n=3)在2.2%~9.8%之间,结果表明该方法用于液体样本中农药残留检测真实可靠。     

多酚原位固化茶渣对水中Cr（Ⅵ）的吸附

通过甲醛与茶渣中多酚类组分的反应制备了多酚原位固化茶渣吸附材料,并将其用于对水中Cr（Ⅵ）的吸附。表征结果显示：茶渣多酚的原位固化提高了其热稳定性,同时对茶渣粒料起到了修补增强作用。固化茶渣对Cr（Ⅵ）的吸附量随溶液pH的减小而增大。在吸附温度303 K、初始Cr（Ⅵ）质量浓度60 mg/L、吸附剂投加量1.0 g/L、吸附时间300 min、溶液pH为2的条件下,固化茶渣对Cr（Ⅵ）的吸附量为56.56 mg/g,去除率达94.3%。固化茶渣对Cr（Ⅵ）的吸附符合Langmuir等温吸附模型和准二级动力学方程,吸附是一个自发的、吸热过程,303,318,333 K下的Langmuir饱和吸附量分别为83.26,107.64,129.20 mg/g。     

Dissipation of carbofuran and carbaryl on Oolong tea during tea bushes,manufacturing and roasting processes

Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol-N-methylcarbamate) and carbaryl (1-naphthyl-N-methylcarbamate) are insecticides widely used in tea plantations. The objective of the present study was to evaluate the dissipation of carbofuran and carbaryl during the growth periods of Oolong tea, processing and roasting. Analysis of the residual insecticides was carried out using high-pressure liquid chromatography with a post-column fluorescence detector. Results showed that in the tea field carbofuran dissipated faster then carbaryl. Manufacturing processes of Oolong tea further reduced the carbofuran and carbaryl contents. The persistence of carbofuran and carbaryl was decreased with increasing roasting temperature. From the results, we conclude that the presence of carbofuran and carbaryl in tea can be reduced by proper field management, manufacturing and roasting processes.     

屯绿陈茶有效成分提取及茶多酚提纯工艺研究

探讨了从陈茶中提取有效成分和茶多酚的提纯工艺。采用不同物料比、浸提温度、浸提时间的正交实验,通过热水煮提从茶叶中获取水溶性物质。结果表明,当料液比为1：20、90℃、120min时,测得的水提取物固化物量最多可达31％;茶叶水提物固化物、水配比为13：400时与乙酸乙酯萃取茶多酚的得率达23％,茶多糖从总量中提取的得率达2．5％。屯绿陈茶有效成分保留效果良好,具有较好的综合利用价值。     

GC-MS分析鸡树条荚蒾叶化学成分

为了开发利用鸡树条荚蒾这一潜在的民间药用植物资源,采用GC-MS方法对鸡树条荚蒾叶石油醚部分的化学成分进行了分析。经毛细管色谱柱分析分离出56个峰,共确认出其中48种成分;应用色谱峰面积归一法分析各成分的相对含量,含量较高的物质有3-甲基丁酸(40.50%)、2-甲基丁酸(14.49%)、邻苯二甲酸丁基异丁基酯(10.28%)、棕榈酸(6.02%)、α-亚麻酸(4.58%)、β-谷甾醇(3.02%)等,化合物类型主要为脂肪酸、烷烃、脂肪醇、酯类、甾醇类化合物。该方法简便可靠、快速、重现性好,并为鸡树条荚艹迷叶的化学成分研究提供了参考依据。     

Rates of particulate pollution deposition onto leaf surfaces: Temporal and inter-species magnetic analyses

Evaluation of health impacts arising from inhalation of pollutant particles <10 μm (PM₁₀) is an active research area. However, lack of exposure data at high spatial resolution impedes identification of causal associations between exposure and illness. Biomagnetic monitoring of PM₁₀ deposited on tree leaves may provide a means of obtaining exposure data at high spatial resolution. To calculate ambient PM₁₀ concentrations from leaf magnetic values, the relationship between the magnetic signal and total PM₁₀ mass must be quantified, and the exposure time (via magnetic deposition velocity (MV_d) calculations) known. Birches display higher MV_d (∼5 cm⁻¹) than lime trees (∼2 cm⁻¹). Leaf saturation remanence values reached ‘equilibrium’ with ambient PM₁₀ concentrations after ∼6 ‘dry’ days (<3 mm/day rainfall). Other co-located species displayed within-species consistency in MV_d; robust inter-calibration can thus be achieved, enabling magnetic PM₁₀ biomonitoring at unprecedented spatial resolution.     

Antagonism of phenanthrene cytotoxicity for human embryo lung fibroblast cell line HFL-I by green tea polyphenols

Polycyclic aromatic hydrocarbons (PAHs) have been detected in some commercial teas around the world and pose a threat to tea consumers. However, green tea polyphenols (GTP) possess remarkable antioxidant and anticancer effects. In this study, the potential of GTP to block the toxicity of the model PAH phenanthrene was examined in human embryo lung fibroblast cell line HFL-I. Both GTP and phenanthrene treatment individually caused dose-dependent inhibition of cell growth. A full factorial design experiment demonstrated that the interaction of phenanthrene and GTP significantly reduced growth inhibition. Using the median effect method showed that phenanthrene and GTP were antagonistic when the inhibitory levels were less than about 50%. Apoptosis and cell cycle detection suggested that only phenanthrene affected cell cycle significantly and caused cell death; GTP lowered the mortality of HFL-I cells exposed to phenanthrene; However, GTP did not affect modulation of the cell cycle by phenanthrene.     

Determination of lead, cadmium and copper in roadside soil and plants in Elazig, Turkey

The concentrations of lead, cadmium and copper in roadside soil and plants in Elazig, Turkey were investigated. Soil samples were collected at distances of 0, 25 and 50 m from the roadside. The concentrations of lead, cadmium and copper were measured by Flame Atomic Absorption Spectrophotometry (FAAS). A slotted tube atom trap (STAT) was used to increase the sensitivity of lead and cadmium in FAAS. Lead concentrations in soil samples varied from 1.3 to 45 mg kg⁻¹ while mean lead levels in plants ranged from120 ng g⁻¹ for grape in point-4 to 866 ng g⁻¹ for apple leaves in point-2. Lead analyses showed that there was a considerable contamination in both soil and plants affected from traffic intensity. Overall level of Cd in soil samples lies between 78 and 527 ng/g while cadmium concentration in different vegetations varied in the range of 0.8–98.0 ng g⁻¹. Concentrations of copper in soil and plant samples were found in the range of 11.1–27.9 mg kg⁻¹ for soil and 0.8–5.6 mg kg⁻¹ for plants. Standard reference material (SRM) was used to find the accuracy of the results of soil analyses.     

Respirometry-based evaluation of the fate and possible effects of antifreeze on activated sludge

This paper focuses on environmental concerns regarding used antifreeze. It shows the results of laboratory respirometric tests conducted to evaluate the potential impact of antifreeze on activated sludge. In this first step of the study, only the components of virgin antifreeze were addressed, i.e. ethylene glycol, and antifoaming and corrosion inhibitory substances. The plateau resulting from oxygen uptake rate measurements of mixed liquor taken at the end of an aeration tank is used as a reference to evaluate the response of biomass to pulse injection of increasing dosages of new antifreeze, compared to that of formaldehyde, a known toxic compound. While 200 mg/L of formaldehyde steadily decreased the biomass activity (7 mg O2/Lh), there were no toxicity effects for doses up to 5000 mg/L of ethylene glycol from new antifreeze coolant (23 mg O2/Lh, compared to the initial 15 mg O2/Lh for the mixed liquor). It is estimated that ethylene glycol concentration in municipal wastewaters should be several order of magnitude lower then the 1000 mg/L shown to be tolerated by the biomass in this work, but at the present stage, the research does not provide enough information to recommend a definitive management scheme for antifreeze discharge. Many other management issues for used antifreeze must be addressed in future studies before any decision on tolerating sewer discharge in Mexico, as a transitory management option that will conciliate the actual practices with legality, can be made.