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1.
采用二氯甲烷萃取稻田水样品,土壤样品用丙酮-二氯甲烷(体积比为9∶1)混合溶液提取,二氯甲烷萃取,水稻植株样品用乙腈-二氯甲烷(体积比为9∶1)混合溶液直接萃取,用气相色谱法同时测定样品中稻瘟酰胺和咪鲜胺残留。该方法在0.012 2 mg/L~2.68 mg/L范围内线性良好,稻田土壤、田水、水稻植株中稻瘟酰胺的检出限分别为2.75μg/kg、1.83μg/L、3.80μg/kg,咪鲜胺的检出限分别为3.55μg/kg、2.66μg/L、5.62μg/kg。空白稻田土壤、稻田水和水稻植株样品3个浓度水平的加标回收率为80.3%~104%,RSD为3.0%~13.2%。  相似文献   

2.
用二氯甲烷提取稻田水和水稻植株样品中的丙草胺,稻田土壤样品用二氯甲烷-甲醇混合溶剂(体积比为9∶1)提取,再用高效液相色谱仪测定。方法在0.02 mg/L~2.00 mg/L的范围内线性良好,相关系数为0.9998;稻田水、土壤,水稻植株中丙草胺的检出限分别为0.001 mg/L、0.005 mg/kg、0.01 mg/kg;对稻田水、土壤和水稻植株分别做3个浓度水平的加标回收试验,重复5次,平均回收率在75.5%~84.7%之间,测定结果的相对标准偏差为2.0%~10.5%。  相似文献   

3.
采用HPLC法测定烟叶和烟田土壤样品中盐酸吗啉胍的残留,通过对样品前处理条件和仪器测定条件进行优化,使该方法在0.100 mg/L~10.0 mg/L范围内线性良好。烟田土壤、鲜烟叶、烤后烟叶中盐酸吗啉胍的方法检出限分别为32.1μg/kg、22.9μg/kg、46.5μg/kg,空白样品3个质量比水平的加标回收率为79.4%~93.8%,RSD为5.7%~12.3%。将该方法用于研究盐酸吗啉胍在烟叶和烟田土壤中的消解动态,得知盐酸吗啉胍在烟叶中的消解半衰期为24.76 d~27.73 d,在烟田土壤中为13.41 d~16.23 d。  相似文献   

4.
采用GC-FPD(S)法测代森锰锌在黄瓜和土壤中的残留,通过优化前处理和检测条件,使方法在0.007 6 mg/L~3.80 mg/L范围内线性良好,在黄瓜和土壤中的方法检出限分别为5.12μg/kg和2.35μg/kg。黄瓜和土壤3个质量比水平的空白加标回收率分别为91.1%~96.5%和82.4%~90.5%,7次测定结果的RSD为5.0%~6.5%和2.4%~4.1%。将该方法用于研究代森锰锌在黄瓜和土壤中的消解动态,得知代森锰锌在黄瓜中的半衰期为3.63 d~4.77 d,在土壤中的半衰期为4.19 d~7.33 d。  相似文献   

5.
采用全自动石墨消解-原子荧光光度法对土壤总汞进行测定,确定最佳消解时间为1 h,消解液最佳用量为8.0 m L。方法在总汞质量浓度为0.2~2.0μg/L范围内具有良好的线性,相关系数为0.999 9,当取样量为0.500 0 g时,检出限为0.002 mg/kg;测定不同标准土壤样品总汞的结果均在保证值范围内,精密度为4.0%~7.0%,加标回收率为95.0%~108.5%;对甘肃省实际土壤及沉积物样品测定进一步验证了方法的适用性。该法适合大批量样品分析,对于提高工作效率有重要意义。  相似文献   

6.
以硝酸作为消解液,采用微波消解仪对海洋沉积物进行消解,用石墨炉原子吸收分光光度法测定消解液中的Cd和Cr。该方法在0μg/L~10.0μg/L范围内线性良好,Cd和Cr的方法检出限分别为0.04 mg/kg和2.0 mg/kg,实际样品的加标回收率在96.0%~100%之间,RSD为0.3%~5.2%。用该方法与国标法同时测定北部湾海域海洋沉积物实际样品,结果无明显差异,而该方法处理样品更为省时省力。  相似文献   

7.
地表水中SVOCs和氨基甲酸酯类农药同步萃取技术的探讨   总被引:1,自引:0,他引:1  
采用大体积固相萃取富集地表水中SVOCs和氨基甲酸酯类农药,再以气相色谱-质谱和超高效液相色谱-串联质谱联用对目标物定性定量。通过优化固相萃取条件,使SVOCs在0.500 mg/L~10.0 mg/L之间,氨基甲酸酯类农药在1.00μg/L~100μg/L之间线性良好,方法检出限为0.002μg/L~0.009μg/L,加标回收率分别为70.5%~105%和78.5%~124%。用该方法测定某流域地表水,结果邻苯二甲酸酯类物质、多环芳烃类、酚类、硝基苯环类化合物等SVOCs,以及克百威、仲丁威等氨基甲酸酯类农药检出。  相似文献   

8.
土壤样品用正己烷-丙酮(体积比为1∶1)混合溶液提取,配合硅胶小柱净化,用乙酸乙酯洗脱,再用气相色谱-火焰光度法测定待测液中14种有机磷农药残留,方法在0.100 mg/L~1.00 mg/L范围内线性良好,当取样量为10 g时,方法检出限为1.3μg/kg~2.3μg/kg。用该方法测定有机磷的有证标准溶液,结果均在保证值范围内,RSD为2.2%~6.7%。实际土壤样品的13种有机磷农药加标回收率为59.2%~125%(敌百虫除外),敌百虫回收率为0,说明目标物在测定过程中被降解,该方法不适用于敌百虫的测定。  相似文献   

9.
采用固相微萃取技术富集水样中甲拌磷及其代谢产物残留,并用气相色谱法测定。通过优化试验条件,使该方法在0.05 mg/L~1.00 mg/L范围内线性良好,甲拌磷、甲拌磷亚砜和甲拌磷砜方法检出限分别为0.64μg/L、36.1μg/L、1.8μg/L。用该方法测定无公害种植基地的灌溉水样品,3种农药残留均为未检出,水样的加标回收率为60.4%~85.7%,测定5次结果的RSD为3.4%~8.5%。  相似文献   

10.
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   

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.
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.
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   

17.
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   

18.
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   

19.
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   

20.
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   

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