Organotin compounds are ubiquitous contaminants in the environment. The high biological activity of some compounds toward aquatic organisms lead to deleterious impacts in aquatic ecosystems. Here, the aquatic ecotoxicology of organotins is reviewed based on a multidisciplinary approach involving environmental chemical, toxicological, and ecological aspects. Basic results were obtained both with field and laboratory studies, and some of the most important recent results and conclusions are critically reviewed. The contamination of and fate in aquatic systems is reported and linked with effects at different levels of biological organization. Major emphasis is placed on the development of a concept of ecotoxicology that encompasses not only effect assessment alone, but also integrates environmental chemistry with aquatic toxicology. Thereby, the influence of speciation for bioavailability, basic modes of toxic action, and aquatic toxicity are discussed. This case study on organotins allows to a certain extent generalizations to ecotoxicology in general.

Ecotoxicology of organotin compounds.

The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth

This public health statement tells you about manganese and the effects of exposure to it.The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in the nation. These sites are then placed on the National Priorities List (NPL) and are targeted for long-term federal clean-up activities. Manganese has been found in at least 869 of the 1,699 current or former NPL sites. Although the total number of NPL sites evaluated for this substance is not known, the possibility exists that the number of sites at which manganese is found may increase in the future as more sites are evaluated. This information is important because these sites may be sources of exposure and exposure to this substance may harm you.When a substance is released either from a large area, such as an industrial plant, or from a container, such as a drum or bottle, it enters the environment. Such a release does not always lead to exposure. You can be exposed to a substance only when you come in contact with it. You may be exposed by breathing, eating, or drinking the substance, or by skin contact.If you are exposed to manganese, many factors will determine whether you will be harmed. These factors include the dose (how much), the duration (how long), and how you come in contact with it. You must also consider any other chemicals you are exposed to and your age, sex, diet, family traits, lifestyle, and state of health.

Toxicological Profile for Manganese

Amino acid analysis : Hydrolysis, ion-exchange cleanup, derivatization, and quantitation by gas—liquid chromatography

Nanoparticles (NPs), due to their unique physical and chemical properties, especially their minute particle size (⩽100 nm), find applications in numerous industrial, commercial and consumer products. After their end-user applications, these NPs find their way into the environment and food products. The NPs so discharged need to be quantified accurately to determine their toxicity and exposure levels. At this time, there is a need to develop a unified method for their determination. There are plenty of techniques available in the market that were initially used for colloidal particles (e.g., microscopy, spectroscopy and the recent addition of magnetic resonance), but each of these techniques has a certain degree of uncertainty. Further, sample homogeneity, sample preparation, instrument-operating procedures, and statistical practices are likely to add to the complexity of the problem. In this context, this review attempts to understand the widely-used light-scattering techniques, including their theory, practice and real-world use in determination of NPs in environmental and food applications.

Measurement of nanoparticles by light-scattering techniques

Accurate spectral scans of single chromatographic peaks

Geometric and Chemical Discrimination in a Non-Dispersive Flame Photometric Detector

Correlation chromatograms from a triple-detector system

A Pure Rubidium/Quartz Source for Alkali Flame Ionization Detectors

A method has been developed for the separation and qualitative detection of 11 amino acids at the picogram level, which uses a derivatization new to the area of gas-chromatographic analysis. Phosphorus-containing derivatives were selected to allow selective and hypersensitive determination with a modified version of the alkali-flame detector. This method comprises the formation of the N-diethyl phosphate amino acid methyl esters and subsequent gas-chromatographic separation and analysis. The minimum detectable limit for alanine (response-noise, 2:1) was found to be ca. 5 × 10−12 g injected. The method should be applicable to the investigation of very small amounts of naturally occurring amino acids and peptides, as was shown with gramicidin-S. A gas-chromatographic analysis of 250 pg of gramicidin-S was found to yield clearly discernible peaks for valine, leucine, proline, and phenylalanine.

Walter A. Aue

Papers

Accurate spectral scans of single chromatographic peaks

Geometric and Chemical Discrimination in a Non-Dispersive Flame Photometric Detector

Correlation chromatograms from a triple-detector system

A Pure Rubidium/Quartz Source for Alkali Flame Ionization Detectors

Ultramicrodetection of Amino Acids by GLC