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1.
讨论了富集采样法监测空气和废气样品时确定采样体积的主要因素,给出了富集采样法监测空气和废气样品时采样体积的确定方法和实例。  相似文献   

2.
沈菁  黄建 《干旱环境监测》1994,8(3):147-149
对用亚甲基蓝分光光度法测定大气中硫化氢的标准溶液、样品的稳定性、温度对试剂空白的影响等问题进行了一些研究。得出:硫化氢标准使用液用磁性锌氨络盐吸收液配制,冰箱保存至少可稳定2个月;温度对试剂空白值有影响,应根据不同显色温度,确定不同显色时间;绘制标准曲线和样品测定应用同一量器迅速加入显色剂,以提高其灵敏度。  相似文献   

3.
环境样品稀释方法的探讨   总被引:1,自引:1,他引:0  
环境样品分析中,特别是污染源样品分析经常遇到样品浓度高于方法的检出范围。为此,根据不同分析项目的分析方法和质量控制的要求,研究和探讨了样品稀释可采用原始样品、中间样品和分析后样品进行稀释。稀释倍数可根据日常积累的基础资料推算、肉眼观察和简单试验的方法确定。探讨了稀释误差的来源及降低稀释误差的方法。  相似文献   

4.
评定了石墨炉原子吸收法测定土壤样品中镉的测量不确定度。在测定过程中,对样品称量、水分测定、样品消解、样品定容、标准溶液配制、标准曲线拟合等影响不确定度的分量进行了评定。按照《测量不确定度评定与表示》(JJF 1059.1—2012)的规定进行合成,给出了扩展不确定度,镉含量结果的表示式为(0.115±0.015)mg/kg,k=2。  相似文献   

5.
根据中国对室内空气污染监测的实际需要,介绍了室内空气污染监测用氨标准样品的研制方法,包括试剂的验证、均匀性和稳定性检验、分析定值和测定数据的统计检验等方面。氨标准样品采用重量法制备,用纳氏试剂分光光度法对样品进行均匀性和稳定性研究,并进行不确定度评估。研究结果表明,氨标准样品的均匀性良好,室温条件下可稳定18个月以上;在全面分析不确定度来源的基础上,定值结果为0.494 mg/L,不确定度小于3%。与美国同类标准物质进行比对分析,结果具有可比性。可用于氨测定的质量控制、分析方法评价以及实验室能力验证等方面。  相似文献   

6.
空气颗粒物中铅、镉超声浸取-原子吸收测定方法研究   总被引:2,自引:0,他引:2  
用超声波震荡方法对大气滤膜样品进行前处理,提取待测元素。研究了浸取液种类、酸度、浸取时间和干扰因素等,确定了颗粒物样品溶液制备的最佳条件,与流动注射在线富集——原子吸收技术结合,建立了大气颗粒物样品测定Pb、Cd方法。结果表明,方法快速、准确,标准样品测定回收率在97%以上,6次测定方目对标准偏差小于2.6%。  相似文献   

7.
环境样品稀释方法的探讨   总被引:4,自引:0,他引:4  
环境样品,特别是污染源样品,在监测分析中经常要对污染物含量较高的样品进行稀释,使稀释后详品中污染物的浓度量分析方法测定浓度范围内。采取科学的稀释方法,确定适当的稀释份数,不仅可减轻分析工作量,节约分析成本,而且可降低样品中干扰物质的浓度,降低稀释误差,提高监测结果的可靠性。1样品稀释方法及其选择样品的稀释方法很多,本文便讨论根据样品稀释时使用的样品预处理程度分类。如原始样品稀释法,中同样品稀释法,分析后样品稀释法等.1.1原始样品稀释法需要稀释的环境样品中,均可采用原始样品稀释法。原始样品稀释法根…  相似文献   

8.
土壤中有机磷农药分析过程中不确定度的来源及评定   总被引:1,自引:1,他引:0  
土壤中有机磷农药分析过程中的不确定度主要来源于样品采集、运输和保存、前处理及分析这四个环节。以土壤中马拉硫磷的测定为例,分别评定了各个环节产生不确定度的大小。结果表明,样品前处理产生的不确定度对总不确定度的贡献最大。  相似文献   

9.
采用重量法对氮气中1,3 -丁二烯气体标准样品的制备方法进行了研究.依据国际标准化组织(ISO)颁布的“6142气体分析-校准气体混合物的制备-重量法”的标准方法,对标准气体在重量法制备过程中的定值分析、不确定度来源、不确定度估算以及不确定度合成进行了阐述.制备的1,3 -丁二烯气体标准样品量值与同类标准样品量值具有可比性,能够满足环境有机污染物监测工作的需要.  相似文献   

10.
水中放射性核素锶-90测量不确定度的评估   总被引:1,自引:1,他引:1  
阐述了分析放射性核素产生不确定度因素比一般化学分析多的原因,通过采用鱼骨图法分析放射性核素锶-90测量实验中的不确定度和分析计算公式中的有关参数,了解到分析水中放射性核素锶-90时,主要受到样品测量、仪器探测效率、样品化学回收率和样品取样体积等4个方面的不确定度因素影响。  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.
We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g–1 dry wt,respectively). Selenium ranged between 11–47 g g–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM 2 = 0.83), the co-efficients of determination were low tomoderate (range of R 2: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.  相似文献   

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