environmental samples Articles

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Fast Analysis of Environmental Samples, Using Solid-Phase Microextraction (SPME)

by Sigma-Aldrich/Supelco  (Dec. 31, 1998)

Solid Phase MicroExtraction (SPME) is an alternative to conventional sample extraction techniques. In SPME, analytes establish an equilibrium between the sample matrix and a stationary phase coated on a fused silica fiber (Figure A). The fiber is thermally desorbed in the injection port of the GC, which transfers the analytes into the capillary ...

Collect Representative Distribution System Samples

by American Water Works Association (AWWA)  (Jan. 1, 2009)

This article discusses the U.S. Environmental Protection Agency´s (USEPA´s) sample flushing guideline that was recently developed by USEPA´s Drinking Water Optimization Program. The objective of the guideline was to establish a consistent, technically sound approach for collecting representative water quality samples in distribution systems. The ...

Biodegradation Tests for Wastewater Samples

by Challenge Technology  (Jan. 1, 2003)

Biodegradation Tests for Wastewater Samples Biodegradation tests usually involve comparison of the oxygen uptake of a test sample – or gas production for anoxic or anaerobic tests – to that for a readily biodegradable control substrate (usually acetic acid, ethanol, or aniline). While biodegradation characteristics can vary among chemical types ...

A Cleaner Energy Future

by ASTM International  (Oct. 16, 2014)

As renewable energy plays an increasingly important role in the world’s energy portfolio, the standards of ASTM International Committee E44 are helping to pave the way for innovation in clean energy sources. A growing population and improving living standards around the world are causing significant increases in energy demand and competition ...

Viewpoint - Compositing Trihalomethane Samples Can Save Money

by American Water Works Association (AWWA)  (May 1, 1981)

Regulations set by the U.S. Environmental Protection Agency are now in effect for the determination of total trihalomethanes (TTHMs) in water systems that serve populations of 75,000 or more persons. Studies at the Lawrence Experiment Station organic analysis laboratory in Lawrence, Massachusetts indicate that sample compositing reduces analysis ...

Oxygen Uptake of Soil and Compost Samples

by Challenge Technology  (Jan. 1, 2003)

Oxygen Uptake of Soil and Compost Samples The Challenge AER-200 aerobic/anaerobic respirometer is ideally suited to determine in-situ rates of oxygen uptake in soil or compost samples – as may occur in the upper layers of soil under natural atmospheric conditions or in mixed compost reactors. This objective is accomplished by using a ...

SupelMIP SPE for Sample Cleanup and Analysis of Food and Environmental Contaminants

by Sigma-Aldrich/Supelco  (Sep. 5, 2013)

MIP SPE was successfully used for extraction of multiple classes of food and environmental contaminants from difficult matrices, such as egg, oil and flour. • Six nitroimidazoles were extracted from egg and milk with recoveries typically over 90%. • Among NSAIDs compounds, acidic compounds gave good recoveries between 100-115% while ...

Rapid estimation of nuclear magnetic resonance experiment time in low‐concentration environmental samples

by John Wiley & Sons, Ltd.  (Oct. 12, 2012)

Nuclear magnetic resonance (NMR) spectroscopy is an essential tool for studying environmental samples but is often hindered by low sensitivity, especially for the direct detection of nuclei such as 13C. In very heterogeneous samples with NMR nuclei at low abundance, such as soils, sediments, and air particulates, it can take days to acquire a ...

An interlaboratory comparison study for the determination of dialkyl phthalate esters in environmental and biological samples

by John Wiley & Sons, Ltd.  (Jun. 15, 2012)

A series of interlaboratory comparison exercises were conducted to assess the accuracy of dialkyl phthalate ester (DPE) concentration measurements in environmental and biological samples. Five laboratories participated in analyses to determine DPE concentrations in standard test solutions; marine sediments; three certified reference materials ...

Simple and efficient ion imprinted polymer for recovery of uranium from environmental samples

by IWA Publishing  (Jan. 1, 2012)

Ion imprinted polymer material (IIP) was prepared by forming ternary complexes of uranyl imprint ion with 1-(prop-2-en-1-yl)-4-(pyridin-2-ylmethyl)piperazine and methacrylic acid followed by thermal copolymerization with ethylene glycol dimethacrylate as the cross-linking monomer in the presence of 1,1′-azobis(cyclohexanecarbonitrile) initiator ...

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