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1.
吹脱捕集GC/FID法测定海河水中挥发性有机物   总被引:17,自引:1,他引:16  
采用吹脱捕集GC/FID法对海河干流水中挥发性有机物进行定性、定量分析。共检测出 39种挥发性有机物 ,不同化合物的回收率为 84 2 %~ 143 2 % ,相对偏差为 1 5 %~ 9 6 %。当水样体积为 2 5mL时 ,方法检测限为 0 0 0 1μg/L~ 0 4μg/L。  相似文献   

2.
石墨炉原子吸收法测定水中铊的方法改进   总被引:1,自引:0,他引:1  
采用石墨炉原子吸收法测定水中铊,对样品前处理的多个细节进行改进,使前处理过程耗时缩短,回收率提高。试验表明,方法在0μg/L ~50.0μg/L范围内线性良好,相关系数r为0.9995;检出限为2.0μg/L,取样量为500 mL,富集50倍时,方法检出限为0.04μg/L;实际水样测定结果的 RSD 为4.9%~8.4%;实际样品的加标回收率为94.0%~102%。  相似文献   

3.
我国4个大城市空气PM_(2.5)、PM_(10)污染及其化学组成   总被引:52,自引:3,他引:49  
报告了 1 995~ 1 996年在中国的广州、武汉、兰州、重庆 4大城市 8个采样点 PM2 .5 、PM2 .5~ 1 0 和 PM1 0 的监测结果。结果表明 ,1 995年 PM2 .5 年均值浓度为 57~ 1 60 μg/m3,比美国 1 997年颁布的标准值 (1 5μg/m3)高 2 .8~ 9.7倍。PM1 0 年日均值为 95~ 2 73μg/m3。除武汉市 1个对照点外 ,其余 7个监测点的 PM1 0 均超过我国空气质量二极标准 (1 0 0μg/m3)2 8%~ 1 73 % ,比美国标准 (50μg/m3)超过更多 ,说明污染是相当严重的。用 XRF分析了 PM2 .5 、PM2 .5~ 1 0 中 4 2种化学元素 ,结果表明 ,燃煤、燃油和其它工业污染的元素 As、Pb、Se、Zn、Cu、Cl、Br、S在这些颗粒物中有明显富集 ,特别是在PM2 .5 中的富集倍数达数十倍至数万倍 ,对人体健康有很大危害  相似文献   

4.
用自制催化剂和氧化剂进行快速法测定CODcr结果 :1分析标样平均值接近真值。 2用国产 CODcr快速测定仪和 72 1分光光度计便可测到 1 0~ 1 0 0 0 mg/L CODcr。3在 COD浓度较低时曲线有很好的线性关系 ,使得降低快速法的定量下限成为可能。定量下限可达 9.0 7mg/L。 4与经典回流法比较 ,相对误差为 - 0 .4 2 %~ 5.39%。5配制方便 ,成本不到专用试剂的 1 /1 0。快速法测定COD_(cr)的催化剂、氧化剂配制与其定量下限@段柏润$娄底地区环境保护局!湖南娄底417000 @段文明$娄底地区环境保护局!湖南娄底417000 @海梦黎$娄底地区环境…  相似文献   

5.
取 2 50 ml含酚水样的蒸馏液于 50 0 ml分液漏斗中 ,加入 2 .0 ml缓冲溶液混匀 ,此时 p H为1 0 .0± 0 .2。加入 1 .5ml2 % 4 - AAP溶液混匀 ,再加 1 .5ml铁氰化钾溶液混匀。做一试剂空白 ,然后均以蒸馏水为参比 ,显色 1 5min用 1 cm比色皿于波长 51 0 nm处测吸光度。含酚 0~ 50 0 (μg/2 50 ml)时符合比耳定律 ;摩尔吸光系数 1 .2 6×1 0 4L/mol· cm,灵敏度较高 ;检出限为 0 .0 75mg/L;相对标准误差 2 .75% ;回收率 92 .5~ 96 .7( % )。本法在经过显色剂显色后确定水样为高浓度时 ,只需对其直接比色即可测出挥发酚浓度 ,避免重复工作…  相似文献   

6.
1实验方法 :于 2 5ml比色管中加 5μg亚硝酸盐氮标准使用液 ( 5.0 μg/ml)、2 .0 ml1 .0× 1 0 -3mol/L 番红花红 T、4 .0 ml2 .0 mol/L 缓冲溶液( H2 SO4) ,用水定容 ,摇匀。放置 1 0 min,用 1 cm比色皿以试剂空白为参比在 365nm处测吸光度 ,吸光值至少在 1 h内保持恒定。 2变异系数 0 .59%~ 1 .35% ,加标回收率 98.2 %~ 1 0 0 .4 %。 3亚硝酸盐氮在 0~ 1 0 .0 μg/2 5ml内符合比耳定律 ,表观摩尔吸光系数 3.1× 1 0 4L/mol· cm,回归方程y=0 .0 2 67c 0 .0 0 2 ,相关系数 r=0 .9992 ,结果满意。番红花红T紫外分光光度法测定微量亚…  相似文献   

7.
沉积物样品用乙腈-柠檬酸缓冲溶液提取后经HLB-SPE柱净化,采用LC-MS/MS法在MRM模式下测定17种磺胺类和4种四环素类抗生素,通过优化测定条件,使方法在0. 500μg/kg~100μg/kg范围内线性良好。方法检出限为0. 15μg/kg~1. 2μg/kg,2个质量比水平的加标回收率为44. 1%~125%,试验5次结果的RSD 16. 0%。将该方法用于测定厦门近岸海域沉积物中抗生素,共有6种磺胺类和4种四环素类抗生素检出,测定值为0. 3μg/kg~26. 2μg/kg。  相似文献   

8.
微波消解ICP-MS法同时测定大气颗粒物中多种痕量元素   总被引:3,自引:0,他引:3  
采用微波消解电感耦合等离子体质谱法同时测定大气颗粒物中13种元素,选择硝酸体系消解20 min,硝酸加入体积为8 mL。Cu、Ni、Cr、Pb、Al、Mg、Mn、Ca在0μg/L~100μg/L,Ag、Ba、Co、Cd、Sn在0μg/L~5.00μg/L范围内线性良好,除Al、Mg、Ca检出限较高外,其他10种元素的检出限为0.07 ng/m3~1.82 ng/m3(按采样体积0.688 m3、定容体积50 mL计),滤膜样品平行测定3次的RSD≤1.2%,加标回收率在92%~108%之间。  相似文献   

9.
建立了顶空固相微萃取-气相色谱-串联质谱法(HS-SPME-GC-MS-MS)测定水中2,4,6-三氯酚的方法。优化条件下,在1. 00~50. 0μg/L质量浓度范围内线性响应良好(r~2=0. 999 1);检出限0. 224μg/L,测定下限0. 896μg/L;加标样相对标准偏差(RSD)为4. 15%~6. 24%;加标回收率为81. 0%~115%;单个样品检测总时间40 min。该方法萃取与气相色谱-串联质谱分析在线一步完成,操作简便、灵敏度高、抗干扰性强,适用于地表水、生活饮用水、工业废水等水体中2,4,6-三氯酚的检测。  相似文献   

10.
微波消解-氢化物发生原子荧光法测定植物中汞和砷   总被引:2,自引:0,他引:2  
采用微波消解-氢化物发生原子荧光法测定植物中汞和砷,优化了试验条件。汞在0μg/L-1.00μg/L、砷在0μg/L~20.0μg/L范围内线性良好,方法检出限汞为0.005mg/kg(以取0.1g样品消解定容至10mL计),砷为0.010mg/kg(以取0.1g样品消解定容至25mL计),植物样品测定的RSD≤4.5%,加标回收率为90.0%~107%。  相似文献   

11.
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   

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 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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%~107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。  相似文献   

19.
Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes   总被引:6,自引:0,他引:6  
Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.  相似文献   

20.
Citation of cyanobacterial cultures from the shores of south west coast of Gujarat, India and their relationship with sea water quality, influenced by extensive pollutant runoff is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of suspended solids (60–1000 mg l−1) and nutrients (PO4 P: 1.3–4 μmole l−1 and NO3 N: 12.5–17.8 μmole l−1) were persistent throughout the analysis. Community structure is seen to be influenced by such persistent pollution. Twenty nine cyanobacterial species were isolated belonging to 9 genera of 4 families, with an elevated occurrence of Oscillatoria and Lyngbya species. No heterocystous cyanobacteria were isolated throughout the study.  相似文献   

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