Accumulation of DDT Residues in the Testes of Channa punctatus (Bloch): A Gas Liquid Chromatographic Analysis

Residues of DDT isomers accumulated in the testes of Channa punctatus (BLOCH) were quantitatively estimated by exposing the fish to 2.5 ppm sublethal concentration for 32 days. The study revealed a high accumulation of DDT residues in the testes. The maximum concentration of residues was noted on the 32nd day of the experiment. The DDT isomer accumulated in maximum concentrations was followed by DDE and DDD isomers. The maximum residue concentrations were 0.3221 ppm (DDT), 0.1119 ppm (DDE) and 0.0695 ppm (DDD) on the 32nd day of the experiment. The total DDT residue concentration at the final interval was 0.563 ppm.     

Interpretation of Gas Chromatographic Data in Subsurface Hydrocarbon Investigations

Capillary column gas chromatography (GC) is extremely useful in investigations of subsurface contamination by petroleum hydrocarbons. Fluid samples collected from observation wells are evaluated by GC methods to detect and analyze petroleum hydrocarbons in dissolved and liquid phases. The presence, types and concentrations of many petroleum-derived hydrocarbons dissolved in ground water can be determined. GC analysis can also be used to determine the composition of liquid hydrocarbon products, including gasoline, distillates and heavier oils. The degree of degradation of sampled liquid hydrocarbon product can be estimated from GC information, and this information can be helpful in estimating the length of time the product has been in the subsurface. Determination of the hydrocarbon source and migration path can be made from GC analysis of fluid samples collected at two or more locations.
This paper is intended to demonstrate interpretative techniques that can be used by hydrogeologists to facilitate the detection, identification and mitigation of subsurface hydrocarbons.     

Residues of Chlorinated Hydrocarbons in Fishes: A GLC Analysis

Residues of four chlorinated hydrocarbons, viz. Aldrin, BHC, DDT and Endosulfan, were estimated in twenty fresh water edible fishes using a gas chromatographic technique. The residue accumulation showed a definite relation with the feeding habits of fishes. Omnivorous fishes were found highly contaminated, followed by carnivorous and herbivorous species. Heteropneustes fossilis was the highly contaminated fish with residue concentrations of Aldrin (0.051 ppm), BHC (0.814 ppm), DDT (1.962 ppm) and Endosulfan (0.312 ppm).     

Adsorbed and Bound Residues in Fulvic Acid Fractions of a Contaminated Groundwater – Isolation:, Chromatographic and Spectroscopic Characterization

Humic substances (HS) were isolated from two contaminated groundwater samples (B22 and B53) from a site of a former gas facility. The isolation yielded almost only the fulvic acid fractions (FA). For characterization spectroscopic (UV, fluorescence) and chromatographic techniques (hydrophobic interaction chromatography – HIC as well as size-exclusion chromatography – SEC) were applied. The sample designated B22 FA was collected from the contamination plume whereas the sample B53 FA was collected downstream. Distinct differences were exhibited by these samples. The UV and fluorescence spectra as well as the HIC and SEC chromatograms of the B53 FA sample resemble those of the FA fraction obtained from natural water (groundwater, bog). The HIC and SEC chromatograms reveal the presence of organic compounds in B22 FA which can be derived from coal tar contaminants or their metabolites. Some of the compounds can be extracted from the FA fraction with non-polar organic solvents indicating adsorptive forces between the contaminants and the FA fraction.     

An Improved Gas Chromatographic Method for the Determination of C6–C12 Petroleum Hydrocarbons in Soil Water

In this work, investigations dealing with the determination of hydrocarbons in contaminated soil water are presented. The hydrocarbons under investigation range from low to high volatility compounds. A GC‐FID method was developed that due to its efficiency, routine suitability, relative rapidity, and low cost is suitable for the analysis of complex chemical mixtures of highly volatile hydrocarbons (with boiling points between 69 and 190°C). The standard used was a gasoline mixture with boiling points ranging from 100 to 190°C. For this standard, no supplementary preparation is needed and it is suitable for the whole range of hydrocarbons under investigation. The determination of the hydrocarbon content of the samples was performed applying univariate and multivariate statistical analysis to the experimental data. In the characterization of a contamination with highly volatile hydrocarbons of soil water originating from different depth layers from the chemistry location Leuna (Sachsen‐Anhalt, Germany), the advantages of a multivariate method are demonstrated in exemplary manner.     

Distribution of DDT in sediments off the central California coast

A collaborative sampling cruise off the central California coast was conducted to evaluate contaminant transport pathways along and across the shelf in the spring of 2002. The area has a complex current structure and net transport routes are not known for sure. Sediment characteristics, and organic and trace metal contaminants were analyzed in sediments taken from locations near shore, out to the heads of several canyons. Relative to the continental shelf and Pioneer Canyon stations, DDT was found at higher concentrations in Ascension and Monterey Canyons. Monterey Bay still receives DDT from terrestrial runoff and may be the source of DDT found in Ascension Canyon. DDT concentrations in Monterey Bay biota indicate bioaccumulation is occurring at depth due to continuing input from the shore. Effects on the deep ocean benthic community is unknown.     

唐山断裂带土壤气地球化学特征分析

由于唐山断裂带土壤气地球化学研究成果相对较少，因此于2017—2018年分3期对唐山断裂带5条分支断裂土壤气浓度（包括Rn、Hg、CO₂）和通量（包括Rn、Hg）进行测量，利用土壤气浓度平均值+2倍均方差的方法确定每条断裂异常限。分析结果表明，唐山-古冶断裂和唐山断裂土壤气浓度及通量出现高值异常；2017—2018年M_L1.0以上地震多集中在唐山断裂和唐山-古冶断裂，与土壤气异常分布有较好的相关性；土壤气地球化学空间变化特征能反映断裂带的分段活动性。     

Analysis of Fluorophores of Dissolved Organic Matter in the Suwannee River by Reversed-Phase Liquid Chromatography

Water Resources - Reversed-phase high performance liquid chromatography in combination with a multiwave fluorescence detector has been used to analyze the natural water of the Suwannee River for...     

Analysis of Changes in Magnetic Anomalies in the Largest Underground Gas Storage Area in China

Geomagnetism and Aeronomy - Hutubi underground gas storage (UGS), as the largest UGS in China, operates periodically by performing gas extraction in winter and injection in summer every year. To...     

The sorption behavior of DDT onto sediment in the presence of surfactant cetyltrimethylammonium bromide

The sorption behavior of p,p′- and o,p′-dichlorodiphenyltrichloroethane (DDT) in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) on sediment was studied. Batch experiments were carried out to investigate the kinetics and thermodynamics of the process. The kinetic behavior of these three chemicals on sediment was described by pseudo-second-order kinetic equations, and the isotherms followed the Freundlich model well. The presence of CTAB was able to remarkably accelerate and enhance the sorption of DDT, whereas DDT showed no effect on the sorption of CTAB in our considered concentration ranges. The thermodynamic parameters, such as standard enthalpy change (ΔH⁰), standard entropy change (ΔS⁰) and standard Gibbs free energy change (ΔG⁰) showed that the sorption process of p,p′- and o,p′-DDT was physical, spontaneous and exothermic, and the randomness at the solid-liquid interface increased during the process. In the presence of CTAB, the sorption of DDT showed significantly negative ΔG⁰ and ΔH⁰ values.     

水源污染对姑咱海子泉气汞和气氡观测的干扰分析

2018年12月姑咱海子泉气汞和气氡出现准同步突升异常变化,通过对气汞和气氡仪器观测系统、脱气装置系统、观测环境影响因素等的调查,观测室环境汞污染检查,龙头沟与二道桥CO2和水质加密观测以及四川地区其它同类台站观测资料对比分析,初步认为该变化是由于观测水源被污染,污染的水源又致仪器脱气装置系统出现故障或气路不畅,此次异常变化是一次典型的干扰案例,并不是地震前兆异常。     

Approaches to the Immunochemical Analysis of Non-extractable Triazine Residues in Refractory Organic Substances (ROS) and Characterization of ROS

The tendency of several pesticides to form non-extractable residues requires simple and fast screening methods. Immunochemical methods can meet this demand. They are based on selective and highly sensitive antibody binding to pesticide residues exposed on refractory organic substances (ROS). s-Triazines were used as an example to show the feasibility of this approach. It was proven that under laboratory conditions atrazine was bound to ROS. Antibody recognition pointed to the availability of free ethyl and isopropyl groups exposed at the non-extractable s-triazine residue. Therefore, it is suggested on the basis of antibody selectivities that binding of atrazine to ROS may take place by substitution of the chlorine residue. In the next step, aquatic ROS isolated from surface waters located in an agricultural area were examined for non-extractable s-triazines. ROS from a lake were found to contain bound residues, whereas none were detected in the creek samples. As an outlook the feasibility of serological characterization of ROS is discussed. The novel concept of serotyping is based on the fractionation of ROS by electrophoretic techniques followed by an immunoreaction with polyclonal antibodies directed against different ROS. When immunoelectrophoresis is used, precipitation lines can be compared and checked for identity and cross-reactivity. This approach can form the basis for classifying ROS and determine similarities with unknown ROS.     

穿越克孜尔逆冲断层的输气管道抗震分析

输气管道作为1种薄壁壳体结构,逆冲断层引起的管道压缩变形容易使其破坏。本文以大北南疆输气管道工程为例,探讨了穿越克孜尔逆冲断层的输气管道地震安全问题。在确定管道穿越处的断层倾角、设防断层位错量、表征管土相互作用的土弹簧参数以及钢管容许应变等参数后,采用壳有限元方法,分析了穿越克孜尔逆冲断层的输气管道变形反应。分析结果显示,管道在逆冲断层作用下以压缩应变为主,管道内的最大轴向压缩应变的幅值随着交角的减小而减小。在通过探槽等方法确定断层活动位置后,该管道若以小于或等于11°的交角通过克孜尔断裂,断层引起的最大轴向压缩应变和拉伸应变均在管道相应的容许应变范围内,满足相关规范的抗震要求。     

Analysis of the Groundwater Monitoring Controversy at the Pavillion,Wyoming Natural Gas Field

The U.S. Environmental Protection Agency (EPA) was contacted by citizens of Pavillion, Wyoming 6 years ago regarding taste and odor in their water wells in an area where hydraulic fracturing operations were occurring. EPA conducted a field investigation, including drilling two deep monitor wells, and concluded in a draft report that constituents associated with hydraulic fracturing had impacted the drinking water aquifer. Following extensive media coverage, pressure from state and other federal agencies, and extensive technical criticism from industry, EPA stated the draft report would not undergo peer review, that it would not rely on the conclusions, and that it had relinquished its lead role in the investigation to the State of Wyoming for further investigation without resolving the source of the taste and odor problem. Review of the events leading up to EPA's decision suggests that much of the criticism could have been avoided through improved preproject planning with clear objectives. Such planning would have identified the high national significance and potential implications of the proposed work. Expanded stakeholder involvement and technical input could have eliminated some of the difficulties that plagued the investigation. However, collecting baseline groundwater quality data prior to initiating hydraulic fracturing likely would have been an effective way to evaluate potential impacts. The Pavillion groundwater investigation provides an excellent opportunity for improving field methods, report transparency, clarity of communication, and the peer review process in future investigations of the impacts of hydraulic fracturing on groundwater.     

Estimation of Organic Pesticide Residues in Wines of Moldova

This paper presents the study of pesticide residues in Moldovan wine products originating from traditional agriculture because the appreciation of these compounds is an important aspect of food safety. During 2007–2010, about 3000 analyses of wine samples using GC‐MS were investigated. Persistent organic pollutants (POPs), i.e., α‐, β‐, γ‐HCH, aldrine, and heptachlor were not found in any of the samples. Insignificant quantities of metalaxyl and mefenoxam were found in some wine samples. The missing of POPs in wine products represents an important quality feature. The study showed that if growers comply with rules of phytosanitary treatments and the waiting period is respected, the content of pesticide residues can be reduced to safe limits. Also, the list of approved pesticides must be regularly revised, taking into account the degree of toxicity. Additionally, growers are to be constantly informed about effectuated changes.     

Variations in DDE percentage correlated with total DDT burden in the blubber of fin and sei whales

Total DDT burden and DDE percentage (DDE/DDT+TDE+DDE) in the blubber of fin and sei whales are highly correlated. Total DDT concentration may be an important source of variation for the DDE percentage detected in different individuals of the same population. Such a positive correlation is explained by the intensification of the dehydrochlorinative and differential excretive functions at higher pollutant levels. In the past, variations in the DDE percentage have been attributed to differences in the chronology of DDT input into the ecosystem and assumed to be indicators of population discreteness or changes in the pattern of DDT exposure of a given population. However, changes in the DDE percentage as related to total DDT burden may be important within the observed normal ranges of variation of total DDT residue levels caused by age and sex composition of the population. Therefore, the DDE percentage may be reliably used only when full control of the life history parameters of the sample is achieved and when strict homogeneity among the samples to be compared has been proved.     

Chromatographic separation of diasteriomeric isoprenoids for the identification of fossil oil contamination

In aliphatic hydrocarbon fractions of crude oils eight acyclic isoprenoid alkanes were separated from accompanying n-alkanes and iso-alkanes by high-performance glasscapillary gas chromatography. Four of these: 2,6,10-trimethyltetradecane (V), norpristane (IV), pristane (III), and phytane (II) could be resolved further to reveal a doublet produced by the different diastereoisomers.In these doublets the front peak represents stereoisomers formed during maturation of crude oil while the rear peak indicates the respective hydrocarbons carrying the original biogenic precursor configuration. This appearance of doublets demonstrates the loss of stereospecificity in hydrocarbons derived from phytol (I). By using the front peaks as diagenetic ‘maturity markers’ attributable to fossil fuels, hydrocarbon mixtures extracted from sea water samples contaminated with fossil oil could be investigated in detail. The quantitative relationship between recent biogenic and fossil fuel hydrocarbons could be determined in extracts in the lower boiling point range.