预冷冻浓缩系统与气相色谱-质谱联用测定空气中挥发性有机物

采用预冷冻浓缩系统和气相色谱-质谱联用,建立了测定空气中39种挥发性有机物的分析方法,该法用苏玛罐或Tedlar气袋采集空气样品经-160℃液氮预冷冻浓缩后,用GC-MS检测.该方法采样简便,灵敏度、准确度高,已应用于室内空气和环境空气的测定,取得满意的结果.     

固相微萃取与气相色谱-质谱联用测定饮用水中甲基叔丁基醚

采用固相微萃取与气相色谱-质谱联用测定饮用水中甲基叔丁基醚(MTBE),研究了萃取头涂层材料、萃取温度、盐浓度、萃取时间和溶液的pH值等操作条件对分析方法的影响.该方法分析MTBE的线性范围0.01-10μg/L,检出限0.66ng/L.0.01μg/L的MTBE水样五组平行测定实验中,相对标准偏差为4.8%.用所建立的方法测得大兴某地下水中MTBE的含量0.8μg/L,加标回收率达到90%.     

全球大气汞排放清单研究现状

综述了全球大气汞排放清单研究现状,结果表明,2010年全球排放汞约1 960 t,其中东亚和东南亚地区约占39.7%,在排放来源方面黄金生产和煤炭燃烧分别占37%和24%。介绍了美国、英国和日本的汞大气排放清单,指出中国在汞排放研究方面与发达国家之间还有差距,建议建立详细的汞排放清单,准确掌握汞的使用和排放现状。     

关于改进非甲烷总烃测定方法的探讨

根据非甲烷总烃排放标准、分析方法和实际监测情况,对非甲烷总烃定义、总烃峰型异常、氧峰干扰、方法检出限测定和采样容器选择等方面存在的问题进行了探讨。结果表明：气态烃的衍生物属于非甲烷总烃,烃的衍生物和色谱柱类型是导致总烃峰型异常的主要原因,使用除烃空气作载气可消除氧峰干扰,非甲烷总烃为差值结果,应按照EPA SW-846标准测定检出限,PVF气袋本底低、气密性和化学惰性好,是最佳的非甲烷总烃采样容器。     

气相色谱/质谱法测定水中15种酞酸酯类化合物

采用固相萃取-气相色谱/质谱法测定水中15种酞酸酯类化合物,确定方法的最优条件为:依次用10 m L正己烷和丙酮混合溶剂(V/V=5∶1)、甲醇和空白试剂水活化C18固相萃取柱后,水样以5 m L/min过柱萃取,再以8 m L正己烷:丙酮(V/V=5∶1)混合溶剂洗脱后,浓缩至1 m L,进气相色谱/质谱测定。该法的检出限为0.18~0.38μg/L,在0.50~20.0 mg/L范围内线性良好,相关系数均0.996。空白水样的加标回收率为71.8%~120%,相对标准偏差为1.73%~12.7%;实际废水水样的加标回收率为64.8%~135%,相对标准偏差为2.75%~18.0%。     

Effects of As levels on radial oxygen loss and As speciation in rice

Greenhouse experiment was conducted to examine effects of arsenic (As) on iron plaque formation, radial oxygen loss, As accumulation, and speciation in rice. Three genotypes were grown in soil with three different concentrations of As. The stress of As caused a slight increase of iron plaque formation (P?>?0.05) and a decrease in the rates of radial oxygen loss (ROL; P?<?0.01). The results of As speciation showed that the percentages of DMA increased from 19–28 % to 53–58 %, while the percentages of inorganic As decreased from 53–58 % to 36–42 % with the increasing soil As concentrations, indicating a strong environmental influence on As species in rice grain. The present study showed that elevated soil As may induce As toxicity towards rice plants, leading to the decrease of ROL; environmental factors could influence As methylation or As species transportation. Our study provided useful information on As tolerance and accumulation in rice which may contribute to reducing the health risk posed by As contamination in rice.     

干酵母生产废水处理方案的改造及应用

干酵母生产废水是一种高浓度有机废水,COD高达13,000mg/L,色度在900倍以上。原方案采用厌氧、硝化(曝气)、反硝化、化学混凝等工艺,但水质不能达到排放标准,且运行成本高。采用EM(有效微生物)技术对原方案进行改造后,废水处理收到较好的效果,并降低了运行成本。     

基于海湾空间的海洋经济差异分析——以辽东湾、渤海湾、莱州湾为例

以辽东湾、渤海湾、莱州湾为海湾地理空间尺度,引入泰尔指数和变差系数、灰色关联法研究三大海湾地区的海洋经济规模总量和海洋产业关联效应的差异,运用多种预测模型预测未来十年三大海湾间地区海洋经济对区域经济发展影响和贡献的差异。结果显示:三大海湾空间地区海洋经济差异呈现先增大后减小趋势,2007年后呈现协调优化发展趋势;滨海旅游业、海洋交通运输和海洋油气业、海洋交通运输和海洋渔业分别对应辽东湾、渤海湾、莱州湾三大经济区的拉动效应较大,形成各具区域特色的重要优势海洋产业;据模型预测结果分析,到2015年辽东湾、渤海湾、莱州湾地区海洋经济比重将分别达到34%、21%、25%;莱州湾、渤海湾的海洋经济直接贡献率分别平均以2%和1%的速度递增,而辽东湾则平均以0.1%的速度递减,到2020年辽东湾、渤海湾、莱州湾的海洋经济直接贡献率将分别为36%、29%、46%。     

Nano-TiO2 enhances the toxicity of copper in natural water to Daphnia magna

The acute toxicity of engineered nanoparticles (NPs) in aquatic environments at high concentrations has been well-established. This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO₂ remarkably enhanced the toxicity of copper to Daphnia magna by increasing the copper bioaccumulation. Specifically, at 2 mg L⁻¹ nano-TiO₂, the (LC₅₀) of Cu²⁺ concentration observed to kill half the population, decreased from 111 μg L⁻¹ to 42 μg L⁻¹. Correspondingly, the level of metallothionein decreased from 135 μg g⁻¹ wet weight to 99 μg g⁻¹ wet weight at a Cu²⁺ level of 100 μg L⁻¹. The copper was found to be adsorbed onto the nano-TiO₂, and ingested and accumulated in the animals, thereby causing toxic injury. The nano-TiO₂ may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification by metallothioneins.     

东江干流富营养化评价及区域差异性研究

利用综合营养状态指数评价东江富营养化状况.结果表明,东江富营养化程度较轻,干流绝大部分区域(96％)为中营养及中营养以下水平,只有少数区域(4％)达到富营养水平.同时,东江干流富营养化程度区域差异性明显,从上游至下游河口富营养化程度逐渐加重.针对东江水质污染现状,建议东江水体管理应以保护为主,同时采取有效措施,改善下游...