Potentially toxic elements in some fresh water bodies in Ethiopia

A total of thirty three water samples were collected from Tinishu Akaki River, Lake Awassa, and Lake Ziway, Ethiopia. Multi-element determination of trace elements (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Ag, Cd, Sn, Hg, and Pb) in water samples was carried out by inductively coupled plasma-mass spectrometry after acidification with 1% HNO₃. The concentration (in µg?L^?1) of the elements were in the range of 1.0–19, <0.42–83, 1.1–1580, <45–1760, <0.11–2.0, 0.43–13, 0.77–13, 6–300, <0.94–2.0, <0.3–1.5, <0.012–0.63, 0.13–4.8, <0.29, and 0.2–7.2 for V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Ag, Cd, Sn, Hg, and Pb, respectively. The concentrations of all the quantified elements, with the exception of Mn, were in the range of the permissible limits of the Ethiopian, European Community, and World Health Organization for both drinking water quality guidelines and irrigation water guidelines. The accuracy of the method was validated by analyzing trace elements in water standard reference material (SRM 1643e). The measured values of trace elements in the SRM agreed well with the certified values at the 95% confidence level.     

Concentrations of some elements in the sediments of a river in Anhui Province,China

A total of 49 sediment samples from New Bian River near the city of Suzhou in northern Anhui Province, China, were analyzed by inductively coupled plasma-mass spectrometry for As, Cr, Pb, Cu, Fe, Zn, Mn, and Ni. Geoaccumulation indices (I_geo) were used to assess the influence of human activities. Correlation analysis and principal component analysis were also performed. The geoaccumulation indices were in the order of As > Cu > Cr > Ni > Mn > Zn > Pb > Fe, the first four of which had values above 0.5. We considered New Bian River to be moderately contaminated with As, Cr, Cu, and Ni. Correlation analysis and principal component analysis indicated that the presence of Fe, Cu, Ni, Mn, Zn, and Pb in New Bian River was caused by soil or rock weathering, whereas the elevated levels of As and Cr depended upon urban, agricultural, and industrial factors. The sampling stations around the towns were dominated by Component 2 (As and Cr), and the sampling stations that distributed along New Bian River were dominated by Component 1 (Fe, Cu, Ni, Mn, Zn, and Pb).     

低温等离子体氧化甲烷的实验研究

采用电容耦合等离子体对干空气中的甲烷进行氧化实验,对甲烷的分解效率、反应产物进行了分析。并且和放置催化剂时进行对比,结果表明放置催化剂后,甲烷的分解效率明显提高,反应产物中CO2 的选择性增加。甲烷的最终氧化产物都为CO、CO2 和H2 O。     

厌氧膜生物反应器污泥组分对膜污染的影响

对一体式厌氧膜生物反应器污泥进行离心分离,考察污泥各组分和膜污染的特性之间的关系.通过对已有理论模型进行变形,推导出阻力的数学模型方程式,并分析了膜通量、膜阻力的变化.同时对混合液悬浮固体进行了颗粒粒径分析,并与好氧膜生物反应器的污泥颗粒进行了对比分析.结果表明,污泥混合液悬浮固体形成阻力占膜总阻力的70%,胶体物质形成阻力占22%,溶解性物质形成阻力占8%.     

氨基化有机-无机杂化整体柱分离富集环境水中五价砷

将四乙氧基硅烷(TEOS)和N-(β-氨乙基)-γ-氨丙基三乙氧基硅烷(AEAPTES)作为共聚前体,采用在毛细管内原位聚合的方式制备得到氨基功能化的有机-无机杂化整体柱,将其作为针式固相微萃取(SPME)介质,建立了现场分离富集环境水中As(V)的SPME方法,优化了有机-无机杂化整体柱富集As(V)的实验条件,并研究了整体柱对As(V)的吸附/洗脱性能和富集能力,实现了环境水样中As(V)的高效、快速、高选择性检测。     

高效液相色谱-电感耦合等离子体质谱法测水中不同形态砷

采用高效液相色谱(HPLC)分离水中两种常见的砷形态As(III)、As(V),电感耦合等离子体质谱系统进行检测鉴定,利用C8色谱柱,探讨了甲醇含量、磷酸二氢钾浓度、四丁基氢氧化铵浓度、p H等测试条件,由此建立了水中砷形态的分析方法。结果表明,以1.5 mmol/L磷酸二氢钾、2 mmol/L四丁基氢氧化铵(TBAOH)、5%甲醇作为流动相,调节流动相为p H 5.5,流速为1.4 m L/min,上述两种不同形态的砷可在5.5 min内得以有效分离,As(III)、As(V)检出限分别为0.001、0.01μg/L,定量下限分别为0.005、0.03μg/L。该方法实现了对水中常见的不同形态砷(As(III)、As(V))的同时分析,具有灵敏度高、选择性好、检测速度快的特点,在水质分析领域具有重要意义与应用价值。     

固相萃取-电感耦合等离子体质谱测定自然水体痕量钍和铀

自然水体中Th和U的浓度极低，尤其Th的浓度单位仅为ng/L,定量测试非常困难。该研究建立了一种NOBIAS PA1螯合树脂萃取结合电感耦合等离子体质谱(ICP-MS)同时测定自然水体中痕量Th和U的分析方法。该方法首先使用UV/H₂O₂法消解水样30 min,去除水体中的有机物，然后在pH=3.00±0.05条件下，将水样以2 mL/min流速通过树脂对Th和U进行富集，使用NH₄AC-HAC溶液去除树脂上吸附的盐类，最后用1 mol/L超纯硝酸对样品进行洗脱，用ICP-MS测试。分析结果显示：Th和U的流程空白值分别为0.47、0.22 ng/L,检出限分别为2.9、2.3 ng/L,测定下限分别为11.46、9.11 ng/L。将该方法应用于不同有机物浓度的咸水和淡水中，结果显示：Th和U的回收率分别为97%～104%和98%～103%,相对标准偏差分别为3%～6%和1%～3%。说明该方法具有较高的回收率、精密度和准确度，适用于自然界各种不同水体中Th和U的定量分析。     

电感耦合等离子体质谱技术在环境监测中的应用进展

电感耦合等离子体质谱技术(ICP-MS)是目前发展最快的痕量元素分析测试技术之一。由于该技术提供了极低的检出限、极宽的动态线性范围,干扰少、分析精密度高,可进行多元素同时快速分析,可与多种分离技术及样品前处理方法和进样方法相结合等优点,得到了迅速的发展。介绍了ICP-MS的基本原理及仪器构造、与其他分析测试技术的比较及发展趋势,并着重介绍了其在环境监测和环境科学研究领域的应用。     

溴化衍生-三重四极杆气质联用法测定地表水中丙烯酰胺

采用溴化衍生-液液萃取法处理地表水,用三重四极杆气相色谱质谱联用仪测定样品中α,β-二溴丙烯酰胺,再换算成丙烯酰胺的质量浓度,该方法在20.0μg/L~500μg/L范围内线性良好,相关系数r为0.998,方法检出限为0.08μg/L。实际水样2个质量浓度水平的平均加标回收率分别为87.5%和92.2%,7次测定结果的RSD分别为9.1%和6.1%。用该方法测定黄河兰州段的黄河水和实验室自来水,结果均未检出。     

高效液相色谱-电感耦合等离子体质谱联用测水中有机汞

建立了高效液相色谱-电感耦合等离子体质谱联用技术(HPLC-ICP-MS)测定水样中甲基汞、乙基汞、苯基汞等3种有机汞的分析方法。采用醋酸铵-L-半胱氨酸缓冲盐及甲醇体系组成的流动相按一定比例进行梯度洗脱,Agilent Zorbax Plus C18柱分离,经前处理的水样在液相色谱中分离后,进入电感耦合等离子体质谱检测其甲基汞、乙基汞、苯基汞的浓度。3种有机汞化合物均在0.50~50.0μg/L范围内呈良好的线性关系,线性相关系数均大于0.999 5。仪器检出限为0.09~0.12μg/L,方法检出限为0.4×10-6~0.6×10-6mg/L,3种有机汞样品加标的RSD均小于11.3%,2个水平的加标回收率为74.4%~83.2%。