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1.
液液萃取-HPLC-ICPMS联用技术测定水体中甲基汞   总被引:1,自引:1,他引:0  
建立了二氯甲烷萃取,半胱氨酸-乙酸铵溶液反萃取,液相色谱-电感耦合等离子体质谱法测定水中甲基汞的方法。取样量为1 L时,方法检出限为0.1 ng/L,相对标准偏差为6.6%~13%,地表水、生活污水和工业废水3种实际水样的加标回收率分别为45.6%~70.5%、37.0%~65.6%、18.4%~61.8%。与5种甲基汞测定方法的前处理过程、分析仪器和检出限进行了比较,并讨论了无机汞的干扰情况及如何降低体系空白和消除无机汞干扰的质量控制手段。  相似文献   

2.
为解决测定受有机物污染的城镇污水原水中氰化物含量过程中出现的总氰化物未检出,进出水总氰化物浓度倒大等问题,采取增加石油醚(90~120℃)萃取或银盐沉淀预处理的步骤,实现对干扰的消除,方法相对标准偏差在4.8%~26.5%之间,加标回收率在84%~90%之间。  相似文献   

3.
采用固相微萃取-气相色谱/质谱联用法测定水中18种酚类化合物,优化了溶液pH值、萃取时间、萃取温度、搅拌速率等萃取条件。方法在0.110 mg/L~1.61 mg/L范围内线性良好,18种酚类化合物的检出限为0.001 mg/L~0.015 mg/L(SIM)和0.003 mg/L~0.035 mg/L(SCAN),污水样品加标回收率为88.4%~97.4%。  相似文献   

4.
固相萃取-液相色谱-串联质谱法测定水中5种雌激素   总被引:1,自引:1,他引:0  
建立了固相萃取-液相色谱-串联质谱组合联用技术同时测定地表水、饮用水和污水处理厂出厂水中的5种雌激素(17β-雌二醇、雌三醇、雌酮、17α-炔雌醇、己烯雌酚)的方法。水样经过全自动固相萃取仪富集,以OASIS HLB柱为萃取柱,甲醇为洗脱剂,用液相色谱-串联四极杆质谱联用仪分析定量。分别在0.5~8、5~80μg/L范围内线性良好,相关系数为0.995~0.998。17β-雌二醇、雌三醇、17α-炔雌醇的检出限均为5μg/L,雌酮与己烯雌酚的检出限为0.5μg/L。5种雌激素的纯水加标回收率为63.6%~120.2%,地表水加标回收率为59.8%~91.5%,自来水加标回收率为55.3%~92.1%,精密度为3.7%~10.7%,该方法简单、可靠,可用于水中雌激素类污染物的同时测定。  相似文献   

5.
应用磁性分散固相萃取技术对环境水体中有机磷化合物进行萃取测定,并对萃取剂的用量、萃取时间、解吸溶剂、盐度等实验影响因素进行了优化。在优化条件下,有机磷的回收率为80.1%~93.1%,相对标准偏差为4.6%~5.9%,检出限为0.000 2~0.000 4 mg/L。与传统的液液萃取及固相萃取相比,该磁性分散固相萃取方法操作更为简单、迅速,有机溶剂消耗量很少,方法环保。能很好的满足环境水体中有机磷化合物的测定。  相似文献   

6.
采用在线蒸馏-无人值守连续流动分析法对污水中氨氮进行检测,方法在0.00~10.0 mg/L范围内线性良好,检出限为0.014 mg/L,实际样品测定的相对标准偏差为1.24%~4.15%,加标回收率为93.0%~108%,精密度和准确度均能满足污水中氨氮的测定要求。  相似文献   

7.
建立了一种小体积液液萃取气相色谱法快速测定地表水中硝基苯类化合物的分析方法。方法具有适用性广、溶剂用量少和操作简便等特点。当萃取剂甲苯用量为1.5 ml时,萃取富集效率可达191~332倍,回收率为90.7%~102%,相对标准偏差为2.9%~5.1%,检出限为0.000 3~0.005 mg/L。  相似文献   

8.
建立了一种液-液小体积萃取GC-MS快速测定地表水中氯苯类化合物的分析方法。该方法具有操作简单快速、适用性广和试剂用量很少等特点。当萃取试剂用量为2ml时(约为一般常规液-液萃取用量的数十分之一),萃取富集效率可达300~500倍,回收率为93%~98%,相对标准偏差为4%~8%,检出限为0.1~0.3μg/L。  相似文献   

9.
采用分散液液微萃取-气相色谱法测定地表水中松节油,通过试验优化萃取剂、分散剂的种类和用量、盐度等影响萃取效率的条件,使该方法在10.0μg/L~500μg/L范围内线性良好,方法检出限为1.6μg/L。用该方法测定实际水样,结果未检出。实际水样的3个质量浓度水平加标回收率为83.6%~104%,RSD为2.1%~8.3%。  相似文献   

10.
采用分散液液微萃取与气相色谱/质谱法联用技术建立了测定水样中四乙基铅的方法。考察了影响分散液液微萃取的因素,包括萃取溶剂、分散剂、萃取次数、萃取时间和盐效应等。在最佳条件下,四乙基铅的富集倍数为330倍,检出限为0.01μg/L(S/N=3),线性范围为0.10~10.0μg/L,线性相关系数为0. 9992。测定饮用水源水中的四乙基铅,加标回收率为87.7%~105%,相对标准偏差为4.8%~7.3%(n=3)。  相似文献   

11.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

12.
微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬   总被引:25,自引:5,他引:25       下载免费PDF全文
用微波消解-原子吸收光度法测定土壤中铜,锌,铅,镉,镍和铬。通过硝酸-氢氟酸-过氧化氢体系消解液对土壤样品消解,选择出微波最佳消解条件。对硝酸-盐酸-过氧化氢体系消解液和硝酸-氢氟酸-过氧化氢体系消解液进行消解对比试验,发现前者不能将土壤样品完全消解,后者能将样品消解完全,但需将消解液中剩余的酸赶尽,否则测定结果将明显偏低。微波消解土壤与传统电热消解相比,操作简便快速,可提高工作效率。  相似文献   

13.
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> -1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.  相似文献   

14.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

15.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

16.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   

17.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

18.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

19.
This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.  相似文献   

20.
In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside.  相似文献   

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