共查询到20条相似文献,搜索用时 78 毫秒
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采用过氯乙烯滤膜采集、密闭微波消解、电感耦合等离子发射光谱法测定大气颗粒物中铅、镍、铬、铜、铁、锌、锰、钡、镉,优化了试验条件.方法线性良好,各元素的检出限在0.001 mg/L~0.01 mg/L之间,滤膜样品测定的RSD为0.6%~2.9%,加标回收率为96.0%~105%. 相似文献
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研究依据测定不确定度的基本理论和ISO 21748:2017《采用重复性、再现性和正确度评估测量不确定度的导则》,提出了基于中国环境监测分析方法标准多家实验室验证中已获得的数据计算合成标准不确定度的方法,将方法标准中规定的重复性、再现性等指标与合成标准不确定度进行了衔接。分析了近年发布的6项水质监测分析方法标准中钴、铬、钼、钛等4种金属元素的相对合成标准不确定度,结果表明:被测量的浓度是影响方法标准测量不确定度的重要因素。对于火焰原子吸收分光光度法(FAAS)和石墨炉原子吸收分光光度法(GAAS),样品浓度为方法标准测定下限3倍左右时,测定结果的相对标准不确定度可保持在15%以下;对于电感耦合等离子体发射光谱法(ICP-AES),样品浓度为方法标准测定下限3~5倍时,测定结果的相对标准不确定度为12%~17%;对于电感耦合等离子体质谱法(ICP-MS),钛元素浓度为测定下限3倍左右时,相对标准不确定度在15%以下,而钴、铬、钼的浓度在测定下限40~100倍以上时,相对标准不确定度在15%以下。6项方法标准可分别用于《地表水环境质量标准》(GB 3838—2002)以及22项水污染物排放标准钴、铬、钼、钛的达标监测。 相似文献
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为探讨不同消解方式下电感耦合等离子体发射光谱法测定土壤及沉积物中硫的适用性,研究了不同标准物质消解液建立的工作曲线、谱线干扰对分析结果的影响。结合土壤和沉积物来源特点、主成分和待测物含量、干扰物情况,筛选20个典型标准物质分别采用王水水浴法和四酸电热板法进行消解,研究了电感耦合等离子体发射光谱法中3条分析谱线(180.669 、181.972 、182.562 nm)测定样品中硫的情况。结果表明,0.500 0 g样品经10.0 mL 王水(体积比1∶1)沸水浴消解4 h,采用电感耦合等离子体发射光谱仪分析谱线硫181.972 nm建立的18个标准物质工作曲线相关系数高达0.999 9,标准溶液实测浓度相对误差为-6.9%~16%,2个标准物质测定结果的精密度和认定值回收率分别为3.3%~4.3%和90%~96.7%,满足生态环境和自然资源行业的质量控制要求,该方法测定结果与波长色散X射线荧光标准分析方法具有可比性。建立工作曲线的标准物质应考虑待测物和干扰物含量,宜选用标准浓度认定值测试的相对误差而非工作曲线的相关系数作为评价工作曲线优劣的主要技术指标,谱线干扰的理论推导情况和实验结果在趋势上有较好的吻合性。 相似文献
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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
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利用top-down技术评定ICP-MS法测定水中镉的测量不确定度 总被引:4,自引:1,他引:3
根据不同分析人员在连续30周内水质中镉实验室质控样品的分析数据,采用top-down技术中的控制图法评定电感耦合等离子体质谱(ICP-MS)法测定水中镉的不确定度。方法依据《生活饮用水标准检验方法金属指标》(GB/T5750.6—2006 1.5)测定镉质量浓度为2.00μg/L的质控样品,测定均值为2.010μg/L,通过评定,不确定度为0.100μg/L。 相似文献
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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.
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Ellis A. M. Franssen Brigit A. M. Staatsen Erik Lebret 《Environmental Impact Assessment Review》2002,22(6)
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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Clifford A. Hui John Y. Takekawa Sarah E. Warnock 《Environmental monitoring and assessment》2001,71(2):107-121
The San Francisco Bay estuary isused by over one million shorebirds during springmigration and is home to several hundred thousandduring the winter. Most shorebird use occurs in thesouthern reach of the estuary (South Bay). Thereduced water circulation and discharge fromindustrial sources in the South Bay are responsiblefor the highest levels of some trace elements in theestuary. Wintering shorebirds have been found to havestrong site fidelity to areas as small as a fewkilometers in the South Bay, which may increase theirexposure to contaminants near local point sources. Inaddition, different shorebird species foraging at thesame site have been shown to have differentcontaminant burdens. Thus, our objectives were totest whether contaminant burdens differed by species,or whether contaminant burdens differed in shorebirdscollected at adjacent sites. We examined thecontaminant profiles of two species of shorebirds,long-billed dowitchers (Limnodromus scolopaceus)and western sandpipers (Calidris mauri) thatforage together at two sites, Hayward and Newark,separated by 8 km in the South Bay. We usedmultivariate analysis of variance tests to compare thecomposition of 14 elemental analytes in their livertissues and estimated their molar ratios of Hg and Se. Composite samples were used for contaminant analysesbecause of the small body size of the shorebirds. Seven elemental analytes (Ag, Ba, Be, Cr, Ni, Pb, V)were below detection limits in a majority of thesamples so statistical analyses were precluded. Inthe measurable analytes (As, Cd, Cu, Hg, Mn, Se, Zn),we found no significant intra-site differences ofcontaminant profiles for the two species. We pooledthe samples to examine inter-site differences andfound significant differences in contaminant profilesbetween shorebirds at the neighboring sites (P = 0.03). Shorebirds at Newark had higher (P < 0.05) concentrations of As, Cd, and Se than those at Hayward. Dowitchers at Newark had concentrations of Hg and Se which were highly correlated (P < 0.003) in a mean molar ratio of 1:19, similar tothat reported in other birds. In the larger dowitcherspecies, we also examined exposure to 20organochlorine compounds. Organic analyses showedthat the dowitchers had been exposed to DDE, PCBs,dieldrin and trans-nonachlor, but with no significantdifferences in concentrations between Hayward andNewark (P > 0.05). 相似文献
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土壤和底泥中砷、铬、锰测定的前处理技术 总被引:6,自引:0,他引:6
试验了土壤和底泥中砷的前处理技术,其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液,比色法分析。试验表明,用H2SO4-H3PO4-H2O2进行前处理是可行的。方法简单、挥发酸雾少,用标准参考物质检验证明,分解完全,数据准确,有粒较好一致性。 相似文献
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This paper presents the chemical speciation and retention behavior of chromium (Cr), nickel (Ni), and cadmium (Cd) prior to
and after the electrokinetic remediation in glacial till soil. The speciation of the metals was predicted using the chemical
speciation program MINEQL+. The simulations were performed for single-contaminant with only Cr(VI) or Ni, and multi-contaminants consisting of: (1)
Cr(VI), Ni, and Cd; (2) Cr(III), Ni and Cd; (3) Cr(VI), Cr(III), Ni and Cd; (4) Cr(VI), Ni, and Cd with reducing agents; and
(5) Cr(III), Ni, and Cd with oxidizing agent (Mn). The results showed that the speciation and distribution of cationic metals
[Ni, Cd, and Cr(III)] in glacial till soil remain unaffected or slightly affected during electrokinetics. This is attributed
to the high pH buffering capacity of the glacial till, leading the metals to precipitate in the soil prior to and after electrokinetics.
This study showed that during electrokinetics, Cr(VI) existed as anionic complex and migrated towards the anode and the migration
is maximum in case of a single-contaminant system. The study also showed that near the anode in the absence of any reducing
and oxidizing agent, Cr(VI) mostly adsorbed, and some of Cr(VI) reduced to Cr(III) and migrated towards the cathode and finally
precipitated due to high pH conditions. Ni and Cd remain adsorbed or precipitated due to the high pH conditions throughout
the soil. Among the reducing agents, the sulfide had significant effect on the migration of metals compared to ferrous ions.
While in the presence of oxidizing agent (Mn), no noticeable Cr(VI) was found in the soil sample indicating the reduction
of Cr(VI) to Cr(III) and the predominance of reducing conditions due to the presence of naturally occurring iron in the glacial
till soil. Overall, this study provides a reasonable explanation of the speciation and distribution of chromium, nickel and
cadmium during the electrokinetic remediation of glacial till soil. 相似文献
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Besser JM Brumbaugh WG May TW Schmitt CJ 《Environmental monitoring and assessment》2007,129(1-3):227-241
We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district
in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish,
and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites
further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining
sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations
in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean
concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples
from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were
lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations
significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year
of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001,
near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites
during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the
Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in
significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams
without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly
among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring
studies. 相似文献
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The present study demonstrates comparison of Cr accumulatingpotential by the plants of Najas indica Cham. (submerged),Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeatedmetal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulationpotential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions incomparison to N. indica and A. sessilis. The maximumaccumulation of 1378, 458 and 201 g g-1 dw Cr was found in the leaves of V. spiralis, N. indica and A. sessilis, respectively at 8 mg L-1 after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll andprotein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plantswere treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). Theplants of V. spiralis treated with 100% tannery wastewatershowed the maximum accumulation (57.5 g g-1 dw) of Cr in the roots after 10 days of exposure. The plants were foundeffective in removing Cr from solution and tannery effluent. 相似文献
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日本核泄漏事故引发的核危机为人类安全和平地利用核能又一次敲响了警钟.核事故应急工作作为减小核电站危害环境和公众安全的最后屏障,将起到重要的作用,必须做好相关的准备和响应工作.核应急辐射环境监测工作是核应急工作的重要组成部分,在对核应急辐射环境监测进行准备和响应时主要遵循实用性、适用性和适度性并兼顾常规和应急监测的“平战... 相似文献