995 resultados para aquatic community


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Solid-phase extraction (SPE) in tandem with dispersive liquid-liquid microextraction (DLLME) has been developed for the determination of mononitrotoluenes (MNTs) in several aquatic samples using gas chromatography-flame ionization (GC-FID) detection system. In the hyphenated SPE-DLLME, initially MNTs were extracted from a large volume of aqueous samples (100 mL) into a 500-mg octadecyl silane (C(18) ) sorbent. After the elution of analytes from the sorbent with acetonitrile, the obtained solution was put under the DLLME procedure, so that the extra preconcentration factors could be achieved. The parameters influencing the extraction efficiency such as breakthrough volume, type and volume of the elution solvent (disperser solvent) and extracting solvent, as well as the salt addition, were studied and optimized. The calibration curves were linear in the range of 0.5-500 μg/L and the limit of detection for all analytes was found to be 0.2 μg/L. The relative standard deviations (for 0.75 μg/L of MNTs) without internal standard varied from 2.0 to 6.4% (n=5). The relative recoveries of the well, river and sea water samples, spiked at the concentration level of 0.75 μg/L of the analytes, were in the range of 85-118%.

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Agency Performance Report

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Agency Performance Report

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This report details the efforts of the community action network in Iowa.

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This report details the efforts of the community action network in Iowa.

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This report details the efforts of the community action network in Iowa.

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This report details the efforts of the community action network in Iowa.

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This report details the efforts of the community action network in Iowa.

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This report details the efforts of the community action network in Iowa.

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Monthly newsletter for the Iowa Department of Public Health

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Monthly newsletter for the Iowa Department of Public Health

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This document is intended to assist Iowa communities in making informed decisions on combining school and public library services. It provides decision-makers with a means of assessing the feasibility of establishing a combined library and, if the decision is made to proceed, with a Planning Guide that addresses the many areas of library operations that need to be considered if the combined library is to be successful. Alternatives to combining libraries exist. Contracted services provide one such option. There are many areas where school and public libraries can and should collaborate in order to provide better service to the community. These alternatives are also outlined in this document.