首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
介绍了瓶装1μmol/mol臭氧前驱体物监测用氮气中57组分挥发性有机物(VOCs)气体标准物质的研制过程,该气体标准物质严格按照《气体分析 校准用混合气体的制备 第1部分:称量法制备一级混合气体》(GB/T 5274.1-2018)所规定的配制气体标准物质的方法采用称量法制备。建立了GC-MS联用结合选择离子扫描(SIM)的分析方法,研究了目标化合物在气瓶中的均匀性和稳定性。57种目标化合物完全满足美国环保署光化学评估监测站(PAMS)关于臭氧前驱体物VOCs在线监测的技术要求。将气体标准物质分别送至中国环境监测总站和英国国家物理实验室(NPL)进行比对分析,结果良好,表明研制的气体标准物质具有较好的压力均匀性和稳定性,符合使用要求。相对扩展不确定度为5%(k=2),使用有效期为1年,取得国家二级标准物质证书,证书编号为GBW(E)083966。  相似文献   

2.
于2018年4—9月对泰州市环境空气中挥发性有机物(VOCs)组分开展现场观测,结合观测数据分析该市大气中VOCs的时空分布特征。结果表明:观测期间泰州市环境空气中VOCs平均摩尔比为45.1 nmol/mol,其中含氧挥发性有机物占比为57.8%;受周边排放源和地理位置影响,下风向点位的VOCs测定值高于其他点位;VOCs月均最高值出现在6月,与臭氧月均最高值出现时间一致,7—9月气团出现老化,导致臭氧生成能力减弱;观测期间VOCs中甲苯/苯(T/B)比值范围为0.201 9~5.130 3,且大部分T/B比值2,说明溶剂、油气和液化石油气挥发等排放源对泰州市环境空气中VOCs的影响较为显著。  相似文献   

3.
利用罐采样-低温浓缩-气相色谱-质谱联用仪结合冷柱箱技术,建立了一次进样同时分析环境空气中116种挥发性有机物的方法。利用苏玛罐采集环境空气样品,液氮低温冷凝浓缩进样,经配有冷柱箱的气相色谱-质谱法进行分析。通过优化冷凝参数和程序升温条件,最终用-35℃初始柱温成功保留住低碳组分,实现用一根色谱柱同时分离低碳和高碳组分。该方法仪器设备简单,无须安装中心切割器、辅助检测器等复杂配件,方法线性良好,精密度、准确度均满足质控要求,检出限为0.03×10~(-9)~0.10×10~(-9),能够满足环境空气中挥发性有机物的测定要求。  相似文献   

4.
于2019年8—9月,采用大气预浓缩-气相色谱质谱联用仪(GC-MS)对泰州市3个监测点位环境空气中57种挥发性有机物(VOCs)进行分析,并开展了VOCs组成特征、臭氧生成潜势(OFP)、VOCs来源及健康风险评价研究。结果表明:3个点位环境空气中φ(VOCs)范围为1.3×10^(-9)~46.9×10^(-9),平均值为8.5×10^(-9)。烷烃在VOCs中所占比例最大。各点位φ(VOCs)平均值依次为:工业园区>公园路>天德湖公园。公园路点位VOCs中苯系物受汽车尾气排放影响较大,天德湖公园和工业园区点位除了受汽车尾气排放影响,还受到有机溶剂和涂料的挥发影响,主要受本地污染主导。OFP中贡献最大的物质为乙烯,OFP值为5.5μg/m^(3),其次为烷烃。健康风险评价结果显示,各点位VOCs非致癌类风险均较低,处于安全范围内。各点位夏季环境空气中苯对人体均具有一定致癌风险。  相似文献   

5.
研究制作了半挥发性有机物中流量采样装置,将环境空气(包括气相和颗粒物)中的半挥发性有机物采集到超细玻璃纤维滤膜及其后面的吸附剂上,用乙醚/正己烷混合溶剂提取,提取液经硅胶柱净化后,用反相液相色谱分离测定邻苯二甲酸酯类.并对色谱分离条件、样品净化方式、目标化合物在气相和颗粒物上的分布规律及采样器的捕集效率进行了实验.  相似文献   

6.
水中挥发性有机物(VOCs)在线监测系统,实现了超声雾化法气液分离,并结合冷阱捕集解析技术,利用气相色谱质谱法监测水中VOCs。该法在25种VOCs质量浓度0.5~20μg/L范围内线性良好,线性相关系数均0.990,检出限为0.10~0.51μg/L,测定下限为0.40~2.04μg/L。通过与实验室法的比对,说明该法可达实验室监测仪器同等水平。  相似文献   

7.
建立了罐采样-正压进样-气相色谱法测定环境空气中温室气体的分析方法。用正压采样器采集环境空气样品至罐中呈正压状态,用气相色谱仪进行分析,并对氮气空白、除烃空气、不同湿度、不同环境温度、不同罐压及精确控制进样压力等因素进行研究。在最佳实验条件下,N2O、CO2、CH4、SF6和CO的方法检出限分别为7 nmol/mol、1.5μmol/mol、0.1μmol/mol、9 pmol/mol、0.2μmol/mol,标准曲线相关系数均大于0.995,低、中、高浓度水平测定结果相对标准偏差均小于2.0%。利用该法对环境空气样品进行了检测分析,与该站点现有的高精度在线监测仪器同时测定结果进行比对,比对结果较好,该方法适用于城市环境空气和无组织废气中温室气体的准确测定。  相似文献   

8.
以江苏某醋厂为研究对象,使用便携式气相色谱/质谱仪实地采样,定性定量分析该厂挥发性有机物(VOCs)的排放特征及异味物质强度特征。采用美国环境保护署(USEPA)的健康风险评价模型,评估醋厂排放VOCs对周围居民的健康影响,结果表明,该厂排放的VOCs仅导致较强的感官影响,未产生明显的致癌效应。  相似文献   

9.
空气中挥发性有机物(VOCs) 的监测方法研究   总被引:11,自引:4,他引:11  
建立了热脱附仪和气相色谱-质谱联用测定室内空气和环境空气中35种挥发性有机污染物的分析方法,方法的最低检出限为0.1~0.9μg/m3, 20μg/m3挥发性有机物标准经6次的重复测定,其相对标准偏差小于8.4%.该方法已用于室内空气和环境空气的测定,取得令人满意的结果.  相似文献   

10.
气相色谱法同时测定制药企业废气中多种挥发性有机物   总被引:1,自引:0,他引:1  
针对典型制药产品青霉素、阿莫西林、维生素C、对乙酰氨基酚生产过程的挥发性有机物(VOCs)排放特点,建立了吸附-解吸-气相色谱法同时检测制药企业废气中丙酮、乙酸乙酯、异丙醇、苯、甲苯、乙酸丁酯和正丁醇等7种特征VOCs的分析方法。采用活性炭采样管采样-二硫化碳解吸-毛细管色谱柱分离,在解吸时间30 min、柱温35℃保持6 min、30℃/min速率升温到200℃保持2 min的色谱分析条件下,各挥发性有机物可以实现良好的分离;7种物质标准曲线相关系数为0.999 8~0.999 9,相对标准偏差为1.1%~3.2%,检出限为0.004 mg/m3~0.014 mg/m3,7种物质的解吸效率为83.1%~105.1%。结果表明,该方法适用于典型制药企业固定污染源排放废气中特征VOCs的测定。  相似文献   

11.
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:24,自引:5,他引:24       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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

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.
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   

19.
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   

20.
The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ 15N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ 15N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ 15N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ 15N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ 15N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R 2 = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ 15N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ 15N of Spartina relates with the integrated, watershed-sea nitrogen inputs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号