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.
建立了加速溶剂提取、凝胶渗透色谱法净化-超高效液相色谱/串联质谱快速测定土壤中20种磺酰脲类除草剂的方法。土壤经过冷冻干燥、粉碎过筛,用加速溶剂仪提取(ASE),经凝胶渗透色谱净化(GPC),以超高效液相色谱/串联质谱(UPLC-MS/MS)多级监测模式(MRM)外标法进行定性定量分析。结果表明:土壤中20种磺酰脲类除藻剂的检出限为2~5 ng/kg。对同一环境样品进行了3个不同添加量(1、5、10μg/L)的加标回收实验,平均回收率为65. 7%~106. 1%,相对标准偏差为2. 3%~12. 1%。该方法快速、灵敏、准确,可有效应用于土壤中20种磺酰脲类除草剂的快速监测。  相似文献   

2.
采用固相萃取-高效液相色谱法同时测定水中12种磺酰脲类除草剂,样品经磷酸调节pH值为2后,经Watens Oasis HLB SPE柱净化浓缩,乙腈洗脱,选择检测波长为230 nm,以乙腈-水溶液(0.02%磷酸)为流动相梯度洗脱,保留时间在14 min~32 min范围内.12种磺酰脲类除草剂在0.050 mg/L~...  相似文献   

3.
高效液相色谱法测定水中4种酰胺类除草剂   总被引:5,自引:0,他引:5       下载免费PDF全文
采用高效液相色谱法同时测定水中4种酰胺类除草剂,优化了试验条件.方法线性关系良好,检出限敌稗为0.000 5 mg/L,乙草胺为0.002 mg/L,丙草胺为0.005 mg/L,丁草胺为0.005 mg/L,RSD≤5.6%,平均加标回收率在84.1%~95.1%之间.  相似文献   

4.
毛细管气相色谱法测定水中氯苯类化合物   总被引:4,自引:2,他引:4       下载免费PDF全文
采用毛细管气相色谱法同时分离测定水中11种氯苯类化合物.用DB-23毛细管柱分离,电子捕获检测器检测,方法线性关系良好,水中氯苯类的最低检出限分别为:二氯苯0.74 μg/L~0.89 μg/L,三氯苯0.17 μg/L~0.21 μg/L,四氯苯0.07 μg/L~0.11 μg/L,五氯苯0.04 μg/L、六氯苯0.02 μg/L,加标回收率在83.5%~101%之间,RSD在1.4%~5.2%之间.  相似文献   

5.
高效液相色谱法测定水中7种三嗪类除草剂   总被引:1,自引:0,他引:1  
采用液液萃取和固相萃取两种方法预处理,高效液相色谱二极管阵列检测器测定水中7种三嗪类除草剂,选择了合适的检测波长和梯度淋洗条件。方法在0.100 mg/L~2.00 mg/L范围内线性良好,检出限为0.06μg/L~0.15μg/L,水样平行测定的RSD为1.6%~6.5%,加标回收率为95.0%~106%。  相似文献   

6.
高效液相色谱法测定土壤中三嗪类除草剂   总被引:4,自引:0,他引:4       下载免费PDF全文
建立了索氏提取、中性氧化铝小柱净化、高效液相色谱二极管阵列检测器测定土壤中7种三嗪类除草剂的方法,优化了检测波长、提取方法和溶剂、梯度淋洗程序等试验条件。7种三嗪类除草剂在0.10mg/L~2.00mg/L范围内线性良好,检出限为0.84μg/kg~2.07μg/kg,RSD为1.2%~5.6%,加标回收率为95.0%~107%。  相似文献   

7.
采用快速溶剂萃取-固相萃取-液相色谱串联质谱法(LC-MS/MS)测定土壤中8种多溴联苯醚类(PBDEs)化合物,通过优化试验条件,使方法在100 μg/L~1 000 μg/L范围内线性良好,方法检出限为085 μg/kg~125 μg/kg。不同土壤样品的8种多溴联苯醚回收率为68.6%~127%,4次测定结果的RSD为4.8%~27.6%。将该方法用于测定电子废物拆解点周边的土壤样品,结果BDE-209测定值为未检出~168 μg/kg,BDE-183为未检出~560 μg/kg,其余6种BDEs均为未检出。  相似文献   

8.
SPE- GC/MS法测定水中对硝基氯苯和2,4- 二硝基氯苯   总被引:2,自引:1,他引:2  
采用SPE-GC/MS法测定水中对硝基氯苯和2,4-二硝基氯苯,优化了试验条件.对硝基氯苯在1.00 mg/L~80.0 mg/L之间线性关系良好,2,4-二硝基氯苯在1.00 mg/L~50.0 mg/L之间线性关系良好,方法检出限对硝基氯苯为0.6 μg/L,2,4-二硝基氯苯为2.1 μg/L,回收率对硝基氯苯为86.2%~94.7%,2,4-二硝基氯苯为87.3%~95.4%.  相似文献   

9.
采用加速溶剂萃取处理土壤样品,用超高效液相色谱串联质谱法测定样品中15种氨基甲酸酯类农药残留,方法在5.00 μg/L~200 μg/L范围内线性良好,检出限为0.3 μg/kg~0.5 μg/kg,加标回收率为78.9%~116%,6次测定结果的RSD为0.7%~15.7%。试验表明:不同地域的6种标准土壤对15种目标物测定均存在不同程度的基质效应,基质种类、基质质量浓度和农药质量浓度均会影响基质效应强度。  相似文献   

10.
研究了氨水介质中痕量镍阻抑高碘酸钾氧化靛蓝胭脂红的指示反应,建立了动力学光度法测定沉积物中痕量镍的新方法.优化了试验条件,方法在0 mg/L~0.45 mg/L线性关系良好,检出限为0.85 μg/g,相对标准偏差为1.8%~2.4%,加标回收率为97.2%~103%.  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.
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.
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   

14.
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   

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.
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   

18.
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   

19.
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   

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   

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