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1.
本文建立了用纯水直接吸收环境空气的甲醇和丙酮,利用静态顶空进样,气相色谱进行定性定量测定。对顶空平衡温度、平衡时间、盐加入量等因素进行了优化,并对方法检出限、线性范围和加标回收率进行了测定。该方法最低检出质量浓度为甲醇0.04 mg/m~3,相对标准偏差为3.2%~5.0%,加标回收率为85.8%~102%;丙酮0.004 mg/m~3,相对标准偏差为3.8%~6.5%,加标回收率为87.4%~98.2%,适用于环境空气中甲醇和丙酮的测定。  相似文献   

2.
采用动态顶空气相色谱FID法测定水中乙醛、丙酮、甲醇、丙烯醛、丙烯腈、乙腈、吡啶等7种极性水溶性有机物,通过优化动态顶空条件,使该方法在0.157mg/L~7.92mg!L之间线性良好。方法检出限在0.008mg/L~0.048mg/L之间,空白水样的加标回收率为103%~111%,RSD为5.4%~8.7%。用该方法测定某制药企业排口污水和地表水,只有污水中甲醇、乙腈、吡啶有响应值。  相似文献   

3.
以HP-INNOWAX色谱柱(30 m×0.32 mm×0.25μm)为分离柱,火焰离子化检验,外标法定量,考察顶空平衡温度、平衡时间对土壤中有机溶剂残留量测定结果的影响。建立了土壤中正己烷、乙酸乙酯、丙酮、甲醇等有机溶剂残留量的顶空气相色谱分析方法。实验结果表明,在顶空平衡温度为90℃,平衡时间为30 min条件下获得较好的定量结果。正己烷的线性方程为Y=11.49X-4.806、乙酸乙酯为Y=4.997X-2.873、丙酮为Y=9.710X-1.556、甲醇为Y=9.316X-5.956;平均回收率范围为78%~97%,精密度(以相对标准偏差计,n=6)为2.8%~9.4%,检出限分别为0.9、0.2、0.6 mg/L和0.4 mg/L。利用该方法对实际样品土壤中有机溶剂残留量进行了检测。结果表明,该样品中含有正己烷和甲醇,其含量分别为1.9 mg/L和1.1 mg/L。本方法快速、灵敏、准确,适用于土壤中残留溶剂的检测。  相似文献   

4.
采用顶空-气相色谱法测定地表水中松节油,并对顶空瓶的平衡温度、平衡时间,盐析效应和取样量等顶空条件进行优化,使方法在0.200 mg/L~4.00 mg/L范围内线性良好,方法检出限为0.037 mg/L。实际样品2个质量浓度水平的加标回收率为89.3%~108%,RSD分别为5.8%和4.8%。  相似文献   

5.
通过试验,讨论盐析效应、顶空的平衡温度和平衡时间、水样的p H值、色谱条件等对顶空-气相色谱法测定环境水体中吡啶准确度的影响。优化上述条件后,方法在0 mg/L~3.95 mg/L范围内线性良好,检出限可达0.016 mg/L,测定下限为0.064 mg/L。用该方法对地表水和生活污水做3个质量浓度水平的加标回收试验,测定6次结果的RSD为1.7%~5.7%,回收率为93.9%~113%。  相似文献   

6.
建立了在突发性水污染事故中定量分析水样中甲醇、丙酮、乙腈、N,N-二甲基甲酰胺和N,N-二甲基乙酰胺等5种极性有机物的实验室和现场应急监测分析方法。采用顶空-车载气相色谱质谱法用于现场快速定性定量分析;顶空-气相色谱法用于实验室准确定量分析。通过优化顶空及气相参数,在最佳实验条件下测得顶空-气相色谱质谱法中甲醇、丙酮、乙腈、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺等5种化合物的检出限分别为1.0、0.06、0.5、10.0、15.0 mg/L,平行测定7次结果的相对标准偏差分别为2.1%~3.8%,加标回收率为69.4%~104%;顶空-气相色谱法灵敏度高于气相色谱质谱法,检出限分别为0.08、0.01、0.03、1.7、1.7 mg/L,平行测定7次结果的相对标准偏差分别为2.5%~4.1%,加标回收率为78.1%~116%。  相似文献   

7.
建立了顶空-毛细管气相色谱测定水中吡啶丙酮乙腈的方法,不用有机溶剂萃取和浓缩,减少了损失和对环境的污染,具有灵敏度高、检出限低、定量准确、操作简便等特点。当取样量为5ml时,检出限可达到0.006~0.03mg/L级,相对标准偏差为1.0%~2.3%,加标回收率在78.0%~100.2%之间,完全适合水中吡啶丙酮乙腈的测定。  相似文献   

8.
以《水质 苯系物的测定 顶空/气相色谱法》(HJ 1067—2019)为基础,通过选取最优的顶空加热平衡温度和优化色谱柱升温程序,建立了自动顶空进样气相色谱法测定饮用水水源中低质量浓度苯系物的方法。该方法能够实现苯系物组分分离清晰,有效提高了检测效率。采用低质量浓度的苯系物系列溶液绘制校准曲线,在0.10~2.00 μg/mL范围内获得较好的线性关系,相关系数(r)为 0.999 4~0.999 9,检出限为0.001~0.002 μg/mL,相对标准偏差为1.5%~4.5%,加标回收率为880%~980%。该方法能够满足对饮用水水源中低质量浓度苯系物准确、高效的测定要求。  相似文献   

9.
用顶空进样-毛细管气相色谱法测定水中甲醇,实验结果受到顶空条件影响因素较多。本文使用正交试验方法对顶空进样的加盐量、炉温、恒温时间等5个因素进行了优化,确定了顶空进样气相色谱法测定水中甲醇的最佳操作条件,配合DB-624石英毛细管柱和氢火焰离子化检测器,检出限可达到0.33mg/L。用本方法选择实验条件更加科学合理,测定结果更加可靠。  相似文献   

10.
采用顶空-气相色谱法测定地表水中乙酸酯类化合物,并对顶空瓶的加热温度、平衡时间进行优化。优化后,方法在6种乙酸酯类化合物质量浓度0.05~1.00 mg/L范围内线性良好,检出限为4.49~58.5μg/L,RSD为0.61%~2.51%,加标回收率为96.5%~104%,方法便捷、环保、经济,适用于地表水中乙酸酯类的检测。  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
18.
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   

19.
一起河流砷污染事故的处置与监测分析   总被引:2,自引:1,他引:1  
介绍了大沙河砷污染事故的处置和监测分析。多介质排查监测摸清了污染的范围和程度,为治理工作提供了科学依据,污染治理措施有效控制了污染的扩散;监测数据表明,治理措施将水中砷污染物沉降至河床使污染水质达标排放。吸附了大量砷化合物的底泥被清理并进一步处置,多介质跟踪监测应持续进行直至不存在潜在危害。  相似文献   

20.
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   

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