气相色谱法测定人参中BHC残留量

本文研究了一种快速、简便、准确地测定人参中ＢＨＣ残留量的气相色谱法。人参样品经正己烷—丙酮冷浸泡,超声萃取,磺化法处理后,萃取液直接上机测定。本方法对人参中ＢＨＣ各异构体的回收率均在８５％以上。变异系数小于１０％。与其它方法相比,本法耗时少,价格廉,结果准确,适合批量样品测定。     

固相萃取-UPLC-MS/MS法测定水中全氟化合物

水样中全氟辛酸、全氟辛烷磺酸钾、全氟丁酸、全氟丁烷磺酸经弱阴离子交换固相萃取柱富集净化后,用超高效液相色谱-串联质谱法测定。通过优化样品前处理条件和仪器条件,使4种全氟化合物在0.05μg/L~10.0μg/L范围内线性良好,相关系数为0.998 9~0.999 9,方法检出限为0.27 ng/L~0.96 ng/L。空白水样3个质量浓度水平的加标回收率为73.1%~91.3%,6次测定结果的RSD为7.4%~14.3%。     

活性炭吸附紫外分光光度法测定油烟挥发组分

建立了用活性炭作吸附剂、脱芳烃石油醚萃取、紫外分光光度法测定油烟挥发组分的方法。取家用抽油烟杯内的油烟气冷凝液加热到200C的样品萃取液作标准油品,在225nm处测紫外吸光值,绘制校准曲线,相关系数在0．986～0．999之间。实验样品分析结果表明,脱芳烃石油醚对样品中油烟挥发组分萃取率可达90％以上,样品测定重现率达76．7％。红外光谱分析标准油品挥发组分初步认定为烃类、卤代烃类、醇酚醚类、醛酮类、羧酸及其衍生物类、稠环杂环类和胺类等。     

顶空气相色谱法测定土壤中有机溶剂残留量

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。     

顶空-气相色谱-质谱法测定土壤中卤代烃

建立顶空-气相色谱-质谱法同时测定土壤中挥发性及半挥发性卤代烃的方法。实验优化顶空平衡温度、顶空平衡时间及盐度条件,并对优化后方法的线性、检出限、精密度及回收率进行分析。结果表明:29种目标化合物在线性范围内线性良好,相关系数均大于0.997,方法检出限为2.2~5.9μg/kg,样品不同浓度水平加标回收率范围为80.0%~120%,相对标准偏差小于20%。该方法适用于土壤样品中挥发及半挥发性卤代烃的测定。     

复杂物质中总氟的分离与测定

将低温湿法消解和水蒸汽蒸馏相结合,使样品的消解及干扰物的分离在同一体系内完成,以氟离子选择性电极测定复杂物质中的总氟,避免了挥发、转移损失与沾污,结果准确、精密度好、回收率为99.95～110.3％,相对偏差为±1.48％。本法特别适宜于干扰因素多、来源复杂的环境样品中总氟的分离与测定。     

热脱附/气相色谱法测定空气中含硫化合物

以固体CO2为冷却试剂，使空气中含硫化合物有效富集在-70℃条件下TANEX复合吸附管内，样品管在热脱附装置中120℃下解吸后，采用气相色谱脉冲式火焰光度检测器测定硫化氢、甲硫醇、二甲二硫和甲硫醚，优化了试验条件。4种含硫化合物检出限为0.1ng—0.5ng，标准管测定的RSD为12.7％—16.3％，实际气样加标回收率为78.3％—87.7％。     

GC-C-IRMS测定污染场地土壤中苯系物单体碳同位素比值

选取苯系物中的代表性组分苯、甲苯和二甲苯等化合物,通过热脱附、气相色谱质谱条件的优化及方法学考察,建立了热脱附进样-气相色谱-同位素比值质谱(GC-C-IRMS)测定苯系物单体碳同位素比值的方法。结果表明,单体化合物进样量在0.3μg以上均能满足测定要求;与直接进样方式相比,热脱附进样对单体碳同位素比值测定无分馏影响;标准溶液和苯系物土壤样品测定结果的RSD分别为1.0%~1.7%和0.3%~2.6%。     

便携式烟气预处理器技术在比对监测中的应用

对2种便携式烟气预处理器在比对监测中的实际应用进行探讨,通过对2种烟气预处理器工作原理及在实际应用中的监测数据进行分析比较,显示在"高湿低硫"条件下,电子冷凝预处理器析出的冷凝液会造成二氧化硫的损失,在应用中应加快除水,减少烟气与冷凝水接触的时间,并防止冷凝液出现在伴热管线与预处理器烟气入口之间。而便携式Nafion预处理器由于具有独特的干燥性能,抗干扰能力,在"高湿低硫"的比对监测中具有较好的可比性和适用性。     

水中微量五氯酚的气相色谱法测定

提出ＧＣ－ＦＣＤ分析方法测定水中微量五氯酚残留量。水样经萃取分离、衍生后，采用石油醚提取醋酸五氯酚酯，然后进入色谱柱，柱内填充２％ＯＶ－１７＋２％ＱＦ－１／ＣｈｒｏｍｏｓｏｒｂＷ－ＨＰ（８０～１００目），柱温２００℃，Ｎ＿２流量８０ｍＬ／ｍｉｎ，五氯酚酯３ｍｉｎ内出峰，最低检测浓度为０．１μｇ／Ｌ，各种样品回收率均在９０％以上，样品测试结果满意，可用于多种水体中微量ＰＣＰ残留量的测定。     

A New Mathematical Approach in Environmental and Life Sciences: Gene–Environment Networks and Their Dynamics

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.      

微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬

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。     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

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.     

An Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

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.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

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.     

An investigation on biological stability of product water generated by lab-scale and pilot-scale distillation systems

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, 240}Pu,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.     

Cyanobacterial Flora from Polluted Marine Shores

Citation of cyanobacterial cultures from the shores of south west coast of Gujarat, India and their relationship with sea water quality, influenced by extensive pollutant runoff is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of suspended solids (60–1000 mg l⁻¹) and nutrients (PO₄ ⁻P: 1.3–4 μmole l⁻¹ and NO₃ ⁻N: 12.5–17.8 μmole l⁻¹) were persistent throughout the analysis. Community structure is seen to be influenced by such persistent pollution. Twenty nine cyanobacterial species were isolated belonging to 9 genera of 4 families, with an elevated occurrence of Oscillatoria and Lyngbya species. No heterocystous cyanobacteria were isolated throughout the study.     

The Draft of the New German Guideline VDI 3782/8 to Model Automobile Exhaust Dispersion

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.     

Hydrocarbon Utilization in Yeast Isolates Found to Grow in Association with Petroleum in a Polluted Ultisol of Midwestern Nigeria

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.     

Hydrologic–Economic Model for Managing Irrigation Intensity in Irrigation Areas under Watertable and Soil Salinity Targets

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.