Residues In Environmental Samples Research Articles

Analysis of diflubenzuron residues in environmental samples by high-pressure liquid chromatography

Analysis of diflubenzuron residues in environmental samples by high-pressure liquid chromatography

Electron capture gas chromatographic determination of Kepone residues in environmental samples.

The pollution of the environment with Kepone (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one) by an industrial manufacturer of the pesticide resulted in the contamination of several terrestrial media, including biological life, near the entry of the insecticide into the ecosystem. The substrata investigated and for which residue methodology was developed included river sediment, soil, water, shellfish, and finfish. Rigorous extraction techniques utilizing the Soxhlet apparatus and the Polytron tissue homogenizer were required for complete removal of Kepone from the samples. Finfish tissue was the most difficult to analyze. For this type of substratum, a preliminary cleanup by gel permeation chromatography was required to remove most of the lipid material followed by a micro Florisil column elution to eliminate polychlorinated biphenyls (PCB'S). Cleanup of shellfish and other environmental samples was accomplished with a micro Florisil column only. Electron capture gas chromatography was used to analyze the sample extracts. Recoveries of Kepone from fortified samples averaged 84% or greater.

Parathion residues in environmental samples from untreated areas.

Parathion residues in environmental samples from untreated areas.

GLC Retention Times of Pesticides and Metabolites Containing Phosphorus and Sulfur on Four Thermally Stable Columns

Abstract The relative retention times of 138 pesticides and metabolites containing phosphorus and sulfur were determined on packings containing liquid phases OV–101, OV–17, OV–210, and OV–225, using a flame photometric detector. These packings have excellent thermal stability and are likely to find widespread use in pesticide residue analyses, especially for the identification of multicomponent residues in environmental samples or in samples of unknown or indefinite history. Relative retention times were determined isothermally and by temperature programming; the latter procedure was more reproducible and also more useful for analyzing mixtures with widely differing retention times.

Pesticides in the Environment

Applied all over the world, pesticides are some of the most dangerous pollutants of the environment becauseof their mobility and ability to accumulate in the environment and their consequent long-term adverseeffects on living organisms in general and human health in particular. For these reasons, it is essential tomonitor and analyze pesticide residues in the environment. This entry discusses the classification of pesticidesas well as their effects on and their fate in the environment. Since legal regulations have come intoforce stipulating highest permissible levels of pesticides and their residues in the environment, the analyticaltechniques applied are sensitive, selective, and appropriate to the low concentrations of the target analytes.The analysis of environmental samples for the presence of pesticides is very difficult: the processesinvolved in sample preparation are labor-intensive and time-consuming and may be a source of additionalcontamination and error; the low concentration levels of analytes and matrix complexity cause yet moreproblems. The extraction and determination of pesticide residues in environmental samples are discussed,as are the techniques most commonly used in these processes. The difficulties occurring at each stage in theanalytical procedure are outlined.