A high performance liquid chromatography method for determination of gas-phase hydrogen peroxide in ambient air using Fenton's chemistry

A new method for determination of hydrogen peroxide in atmospheric samples is described. Cryogenically collected H2O2 is reacted with sodium salicylate in the presence of Fe(2+) to produce dihydroxybenzoate, which is separated from the reaction mixture by high performance liquid chromatography and detected by UV absorption. Measurements of atmospheric H2O2 were conducted in Las Vegas, NV from June 1999 to December 1999 to evaluate and characterize the method. Measured mixing ratios of H2O2 (there were also non-detects) ranged from 0.012 to 2.74 ppbv, with expected correlations to primary gaseous pollutants and strong seasonal variation consistent with a photochemically derived species. It was concluded that the method is easy to use and has sufficient sensitivity and selectivity to be useful in atmospheric monitoring.     

Communication and mutual resource exchange in north Florida hermit crabs

Summary The patterns of shell exchange in three species of hermit crabs which overlap in distribution and shell use were observed in the laboratory. Crabs showed no tendency to initiate more exchanges with conspecifics as compared with nonconspecific individuals and there were no specific size dominance effects. Lack of common communicatory patterns betweenClibararius vittatus andPagurus pollicaris was correlated with minimal actual exchange, whilePagurus impressus exchanged with both species and executed patterns in common with both. The pattern of shell exchanges and preferences indicated that, in some cases, both individuals may gain in interspecific exchanges.     

Evaluation of soil-washing process for “unwashable” clays and silts from the palmerton zinc site

The Palmerton Zinc Site is a Superfund site in Palmerton, Pennsylvania. Its former mineral processing operations have contaminated nearby wells and soils with zinc and cadmium. Preliminary analysis of soil and dust sampling conducted in May 1991 has revealed that the dust poses a potential threat to human health. Based on the results of a previous study, which showed a high percentage of silt and clay in soils from Palmerton residential properties, it was concluded that soil washing is not likely to be a viable method to treat the soil and dust contamination in Palmerton. However, since the completion of this study, a soil-washing process for “unwashable” clays and silts has been developed. A residential soil sample from Palmerton, which had low concentrations of arsenic, cadmium, and lead, and a somewhat high concentration of zinc, was washed in a bench-scale version of this process. The results showed that the new soil-washing process for “unwashable” clays and silts may be a viable method to treat the soil and dust contamination in Palmerton, depending on the soil quality criteria concentrations selected for site cleanup.     

Rapid prenatal diagnosis of 14 cases of triploidy using fish with multiple probes

Fluorescence in situ hybridization (FISH) of chromosome-specific probes to interphase nuclei can rapidly identify aneuploidies in uncultured amniotic fluid cells. Using DNA probe sets specific for chromosomes 13, 18, 21, X, and Y, we have identified 14 fetuses where the hybridization pattern was consistent with a triploid chromosome constitution. In each case, the identification of fetal abnormalities by ultrasound examination initiated a request for rapid determination of ploidy status via prenatal FISH analysis of uncultured amniocytes. FISH produced a three-signal pattern for the three autosomes in combination with signals indicating an XXX or XXY sex chromosome complement. This hybridization pattern was interpreted to be consistent with triploidy. Results were reported to the physician within 2 days of amniocentesis and subsequently confirmed by cytogenetics. These cases demonstrate the utility of FISH for rapid prenatal identification of triploidy, particularly when fetal abnormalities are seen with ultrasonographic examination.     

Mating success of male hermit crabs in shell generalist and shell specialist species

Summary The reproductive behavior of two species of diogenid hermit crabs was studied in Hawaii. In the shell generalist, Clibanarius zebra, male reproductive success varied little with size, although the largest males were less successful in obtaining copulations than were medium-large males. Male and female size were positively correlated, in successful pairs, thus larger males had the potential to fertilize more eggs when they were successful in obtaining a copulation. Female fecundity in C. zebra was not affected by species of gastropod shell inhabited once female size was taken into account. Male copulatory success was very strongly influenced by the species of gastropod shell inhabited. Males in Trochus or Nerita shells had greatly reduced reproductive success compared to males in Turbo or Nassarius shells. This result was due both to (1) males in Trochus especially dropping and otherwise poorly handling females during precopulatory behavior and (2) females not responding to precopulatory behavior patterns executed by males in Trochus and Nerita. Transferring males from good to bad shapes of shells and vice versa showed that male success was a function of shell type inhabited and not some correlated feature of the crabs. In the shell specialist, Calcinus seurati, which is found primarily in Nerita shells as an adult, males in Nerita shells were quite successful in obtaining copulations.     

Tapping the leakages: Methane losses, mitigation options and policy issues for Russian long distance gas transmission pipelines

The Russian natural gas industry is the world's largest producer and transporter of natural gas. This paper aims to characterize the methane emissions from Russian natural gas transmission operations, to explain projects to reduce these emissions, and to characterize the role of emissions reduction within the context of current GHG policy. It draws on the most recent independent measurements at all parts of the Russian long distance transport system made by the Wuppertal Institute in 2003 and combines these results with the findings from the US Natural Gas STAR Program on GHG mitigation options and economics.With this background the paper concludes that the methane emissions from the Russian natural gas long distance network are approximately 0.6% of the natural gas delivered. Mitigating these emissions can create new revenue streams for the operator in the form of reduced costs, increased gas throughput and sales, and earned carbon credits. Specific emissions sources that have cost-effective mitigation solutions are also opportunities for outside investment for the Joint Implementation Kyoto Protocol flexibility mechanism or other carbon markets.     

A deterministic approach to evaluate and implement monitored natural attenuation for chlorinated solvents

A US EPA directive and related technical protocol outline the information needed to determine if monitored natural attenuation (MNA) for chlorinated solvents is a suitable remedy for a site. For some sites, conditions such as complex hydrology or perturbation of the contaminant plume caused by an existing remediation technology (e.g., pump‐and‐treat) make evaluation of MNA using only field data difficult. In these cases, a deterministic approach using reactive transport modeling can provide a technical basis to estimate how the plume will change and whether it can be expected to stabilize in the future and meet remediation goals. This type of approach was applied at the Petro‐Processors Inc. Brooklawn site near Baton Rouge, Louisiana, to evaluate and implement MNA. This site consists of a multicomponent nonaqueous‐phase source area creating a dissolved groundwater contamination plume in alluvial material near the Mississippi River. The hydraulic gradient of the groundwater varies seasonally with changes in the river stage. Due to the transient nature of the hydraulic gradient and the impact of a hydraulic containment system operated at the site for six years, direct field measurements could not be used to estimate natural attenuation processes. Reactive transport of contaminants were modeled using the RT3D code to estimate whether MNA has the potential to meet the site‐specific remediation goals and the requirements of the US EPA Office of Solid Waste and Emergency Response Directive 9200.4‐17P. Modeling results were incorporated into the long‐term monitoring plan as a basis for evaluating the effectiveness of the MNA remedy. As part of the long‐term monitoring plan, monitoring data will be compared to predictive simulation results to evaluate whether the plume is changing over time as predicted and can be expected to stabilize and meet remediation goals. This deterministic approach was used to support acceptance of MNA as a remedy. © 2007 Wiley Periodicals, Inc.