气相色谱法测定水中有机磷农药

用电子捕获检测器，大孔径毛细管色谱柱直接进水样分析７种有机磷农药。柱容量大，分析速度快，分离效率高地填充柱，灵敏度高于火焰光度检测器。分析精密度和准确度均较小内径毛细管柱高。     

废水中有机磷农药测定的分析方法研究报告

本文用乙酸乙酯一次提取废水中有机磷农药,提取液不必进一步净化和浓缩,而直接用火焰光度检测器测定乐果、稻瘟净、异稻瘟净、甲基对硫磷、马拉硫磷、对硫磷等农药。上述农药在色谱柱上八分钟能全部分离。     

环境背景值中人体血液胆碱酯酶活性的初步研究

有机磷农药进入人体后,通过血流迅速分布至全身各器官组织,主要抑制胆碱酯酶活性人体血液胆碱酯酶(Cholinesterase,简写ChE)对于检定有机磷农药是最灵敏的。因此,人体血液ChE的活性率是分析评价环境中有机磷农药污染状况,防治和研究有机磷中毒的重要指标之一。通常,采用体外ChE抑制试验的方法来判此有机磷农药的毒性。我国各地人体血液ChE的活性率因受地理环境、饮食、生活习惯等因素的影响而有差异。     

稀释介质对测定有机磷农药的影响

用HP6890气相色谱仪氮磷检测器(NPD)测定有机磷农药时，需购买高浓度标准贮备液，使用时进行稀释，实验中发现，稀释的介质对有机磷检测敏感性有一定影响，浓度越低，影响越大。     

气相色谱-脉冲火焰光度检测器测定痕量有机磷农药

在水样和土壤样中分别加入二氯甲烷和丙酮，用超声波提取水样中敌敌畏、乐果、甲基对硫磷、马拉硫磷、对硫磷等5种有机磷农药和土壤样中甲拌磷、二嗪磷、异稻瘟净、杀螟农、溴硫磷、水胺硫磷、稻丰散、杀扑磷等8种有机磷农药，大大地简化了测定的预处理过程。应用气相色谱法HP—5石英毛细管柱分离，脉冲式火焰光度检测器检测，取得了较好的测定结果。水样中农药的检测限≤0．O02mg／L，土壤样中农药的检测限≤0．O02mg／kg，相对标准偏差水样＜7％，土壤样＜10％，加标回收率水样在84％—96％之间，土壤样在80％—108％之间，均满足测定要求。     

环境试样中黄磷的气相色谱测定

应用气相色谱仪氮磷检测器大口径毛细管柱测定地面水,工业废水,底泥和鱼体试样中的黄磷,方法速简便,灵敏度高,并能同时测定某些有机磷农药。     

气相色谱-串联质谱法测定水中痕量有机磷农药和甲萘威

采用二氯甲烷萃取水样，气相色谱-串联质谱法同时测定水中有机磷农药和甲萘威。试验表明：方法在20．0μg/L ～1000μg/L范围内，各目标化合物线性良好；方法检出限为0．004μg/L～0．01μg/L；对实际水样进行3个质量浓度水平的加标回收试验，回收率在71．8％～94．5％之间，RSD为3．7％～8．5％，满足水中痕量有机磷农药和甲萘威的测定要求。     

三氯甲烷中有机磷农药混合标准样品的研制

确立了三氯甲烷中有机磷农药混合标准样品的制备、分析和定值方法，进行了标准样品的均匀性检验、稳定性监测及协作定值数据的不确定度评价。结果表明，三氯甲烷中有机磷农药混合标准样品的均匀性良好，至少在18个月的时间内稳定。     

农药厂周边有机磷农药在生物体中残留的检测方法研究

测定南京某农药厂附近大米、蔬菜及肉类中11种有机磷农药含量，通过使用气相色谱/质谱联用的方法，建立GC／MS定性定量分析方法，检出限达到0．05μg／kg（肉类）和0．1μg／kg（大米和蔬菜），回收率均符合测定要求。环境样品监测结果显示，大米和蔬菜中有机磷农药的含量高于肉类中的含量，说明在大米和蔬菜表面残留的农药量要高于进入生物体体内的含量。南京蔬菜样品中有机磷农药高于常州蔬菜样品，说明农药厂对蔬菜表面残留农药量有影响。不同的有机磷农药在不同的介质中，检出情况不一样，说明不同的环境介质对有机磷农药的保留水平不一样。     

气相色谱法测定蔬菜中有机农磷药残留量

当前我区施用有机磷农药极为普遍。用作蔬菜杀虫剂的有十种之多。用量较大的是敌敌畏、乐果、氧化乐果、甲基对硫磷、对硫磷等五种。所以对蔬菜中有机磷农药残留的测定将成为常规分析。有机磷农药的分析方法有许多文献报导:比色法、极谱法、紫外分光光度法等。这些方法常用于单种有机磷农药成份的分析。薄层色谱法虽可分离多种有机磷农药,与气相色谱法相比定量精度差。后者则有选择性强,灵敏度高等特点。     

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.      

Assessing health consequences in an environmental impact assessment: The case of Amsterdam Airport Schiphol

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.     

Contaminant Profiles of Two Species of Shorebirds Foraging Together at Two Neighboring Sites in South San Francisco Bay, California

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).     

土壤和底泥中砷、铬、锰测定的前处理技术

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。     

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.     

Geochemical assessment of metal transport in glacial till during electrokinetic remediation

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.     

Biomonitoring of Lead, Zinc, and Cadmium in Streams Draining Lead-Mining and Non-Mining Areas, Southeast Missouri, USA

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.     

Comparative studies on accumulation of Cr from metal solution and tannery effluent under repeated metal exposure by aquatic plants: its toxic effects

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.     

Assessment of Air Quality After the Implementation of Compressed Natural Gas (CNG) as Fuel in Public Transport in Delhi, India

Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM₁₀, CO, SO₂ and NO_x) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO₂ and CO concentrations, while the NO_x level was increased in comparison to those before the implementation of CNG. Further, SPM, PM₁₀, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.