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1.
采用全自动固相萃取处理废水,气相色谱-质谱联用法测定废水中的15种硝基苯类化合物,通过优化试验条件,使方法在0.100mg/L~10.0mg/L范围内线性良好。方法检出限为0.012μg/L~0.038μg/L,标准溶液11次测定结果的RSD为1.0%~7.5%。对实际水样做2个质量浓度水平的加标回收试验,平均加标回收率为78.0%~107%。  相似文献   

2.
采用固相萃取-GC-MS/MS法测定水中10种N-亚硝胺类化合物,通过试验优化前处理和测定条件,使方法在0. 500μg/L~100μg/L范围内线性良好。方法检出限为0. 6 ng/L~2. 1 ng/L,混合标准溶液6次测定结果的RSD 5%。将该方法用于测定实际水样,结果除N-亚硝基二甲胺、N-亚硝基甲基乙基胺和N-亚硝基二丙胺以外,其余目标物均为未检出,加标回收率为73. 1%~97. 6%。  相似文献   

3.
采用液液萃取/固相萃取净化/气相色谱法测定废水中9种硝基苯类化合物,通过萃取条件优化试验,选择乙酸乙酯:正己烷=(2:1)为萃取剂,佛罗里硅土柱为净化小柱,目标物在0~1000μg/L之间线性良好,检出限为0.0085~0.156μg/L。实际水样的加标回收率为71%~92%。用该方法测定4批废水,结果其中有硝基苯类化合物虽有检出,但检出值均低于相关标准规定的限值。  相似文献   

4.
本文建立了一种磁性分散固相萃取配合气相色谱-质谱测定地表水中痕量邻苯二甲酸酯的方法。减少了萃取剂的用量、萃取时间、解吸溶剂及盐度对实验结果的影响。在优化条件下,邻苯二甲酸酯类化合物的检出限在0.1~0.7μg/L,回收率在84.2%~111%,相对标准偏差在3.3%~5.5%。与传统的液液萃取及固相萃取相比,该方法具有简便、快捷和灵敏的特点,适用于水中低含量邻苯二甲酸酯类化合物的测定。  相似文献   

5.
本研究建立了固相萃取结合高效液相色谱-串联质谱法测定水样中苯胺类化合物的方法,水样前处理使用PCX固相萃取小柱吸附苯胺类化合物,以甲醇溶剂洗脱,采用ZORBAX Eclipse Plus C18色谱柱,电喷雾质谱正离子模式,以乙腈-0. 2%甲酸水为流动相,梯度洗脱,同时测定水样中12种苯胺类化合物。结果显示,进水中12种苯胺类化合物加标回收率62.3%~119%,日内精密度为2.55%~11.8%,日间精密度为4.17%~13.6%;出水中12种苯胺类化合物加标回收率为70.5%~115%,日内精密度为2.49%~10.5%,日间精密度为3.01%~15.5%;12种物质的检出限为0.25~1.97μg/L。该方法操作简单、结果准确,能够满足水样中12种苯胺类化合物的定性定量测定,可同时处理大批样品。用该方法对江苏省淮安市18家污水处理厂的进、出水样进行了测定,12种苯胺类化合物在18个采样点均能检出,其中N,N-二乙基间甲苯胺检出水平最高,平均值为15.29ng/L,2,6-二甲基苯胺同样检出水平最低,平均值为5.22 ng/L。采用风险商值法评估对12种苯胺类化合物进行了生态风险评估,结果表明二苯胺、苯胺和间甲苯胺为中等潜在生态风险,其他均为低生态风险。  相似文献   

6.
采用磁性分散固相萃取技术富集水中氯苯类化合物,用气相色谱法测定,并对萃取剂的用量、萃取时间、解吸溶剂、氯化钠加入量等条件进行优化。试验表明,方法在0.001 mg/L~2.50 mg/L 范围内,氯苯类化合物各组分线性良好,方法检出限在0.600μg/L~5.00μg/L范围内。地表水实际水样的加标回收率为83.1%~93.4%,RSD为4.8%~7.3%。  相似文献   

7.
采用固相萃取-气相色谱-质谱法(SPE-GC-MS)同时测定水中26种有机氯农药和8种氯苯类化合物,通过选择合适的SPE小柱、优化固相萃取和仪器检测的条件,使该方法在0.050 0 mg/L~1.00 mg/L范围内线性良好。各目标物的方法检出限为0.021μg/L~0.069μg/L,空白水样的加标回收率为36.6%~133%,RSD为0.5%~12.4%。  相似文献   

8.
采用固相萃取-氢火焰离子化检测器气相色谱法测定水中15种酞酸酯类化合物,通过试验优化前处理条件,使方法在0.500 mg/L~20.0 mg/L范围内线性良好,方法检出限为0.20μg/L~0.39μg/L。空白水样的加标回收率为66.6%~120%,试验6次结果的RSD为5.7%~12.5%。用该方法测定实际水样,加标回收率为66.8%~119%,6次测定结果的RSD为5.4%~11.8%。  相似文献   

9.
GC- M S法测定蔬菜和水果中八氯二丙醚   总被引:4,自引:0,他引:4       下载免费PDF全文
建立了固相萃取-GC-MS法测定蔬菜和水果中八氯二丙醚残留的方法,样品采用乙腈均质提取,固相萃取柱净化,正己烷定容.优化了试验条件,选择了定性与定量离子,方法线性良好,最低检出限为0.004 7 mg/kg,加标量为0.10 mg/L~1.00 mg/L时,回收率为87.0%~96.0%,RSD<4.0%.  相似文献   

10.
采用固相萃取-气相色谱/质谱法测定水中15种酞酸酯类化合物,确定方法的最优条件为:依次用10 m L正己烷和丙酮混合溶剂(V/V=5∶1)、甲醇和空白试剂水活化C18固相萃取柱后,水样以5 m L/min过柱萃取,再以8 m L正己烷:丙酮(V/V=5∶1)混合溶剂洗脱后,浓缩至1 m L,进气相色谱/质谱测定。该法的检出限为0.18~0.38μg/L,在0.50~20.0 mg/L范围内线性良好,相关系数均0.996。空白水样的加标回收率为71.8%~120%,相对标准偏差为1.73%~12.7%;实际废水水样的加标回收率为64.8%~135%,相对标准偏差为2.75%~18.0%。  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.
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   

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.
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   

16.
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   

17.
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   

18.
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   

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.
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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