| Calibrate |
| Monday, 19 December 2011 15:59 |
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Fine Tuning Your Knowledge of Current Laboratory Issues The Department of Navy has published The Environmental and Natural Resources Program Manual which discusses requirements, delineates responsibilities, and documents policy for managing environmental and natural resource issues for all Navy ships and shore activities. Chapter 29 of this document, Sampling and Laboratory Testing, contains policy and guidance applicable to environmental sampling and laboratory testing. It identifies requirements and responsibilities for implementing environmental quality systems into Navy activities and programs involving the collection, management, and use of environmental data to ensure that the measurements and collected data are accurate, meet requisite acceptance or performance criteria, and are appropriate for their intended use by the Navy in making decisions concerning the environment. Although the document is dated October 30, 2007, it has just now been published on the Navy website. Complete document: http://www.navylabs.navy.mil/Archive/5090.1C%20Manual.pdf Memory Effects on Adsorption Tubes for Mercury Vapor Measurement The short- and long-term memory effects associated with measurements of mercury vapor in air using gold-coated silica adsorption tubes are described in this article. Data are presented to quantify these effects and to determine their dependence on certain relevant measurement parameters, such as number of heating cycles used for each analysis, age of adsorption tube, mass of mercury on adsorption tube, and the length of time between analyses. The results suggest that the long-term memory effect is due to absorption of mercury within the bulk gold in the adsorption tube, which may only be fully liberated by allowing enough time for this mercury to diffuse to the gold surface. The implication of these effects is discussed, and recommendations have been made minimize measurement bias from this effect. http://pubs.acs.org/doi/abs/10.1021/es201454u Calibration for Monitoring of Organic Contaminants in Fish by Solid-Phase Microextraction Solid-phase microextraction (SPME) is a promising technique for determining organic contaminants within biotic systems. Existing in vivo SPME-kinetic calibration (SPME-KC) approaches are unwieldy due to the necessity of predetermining a distribution coefficient for the analyte of interest in the tissue and the preloading of a calibrating compound to the fiber. In this study, a rapid and convenient SPME alternative calibration method for in vivo analysis, termed SPME-sampling rate (SPME-SR) calibration, was developed and validated under both laboratory and field conditions to eliminate such presampling requirements. The SPME probe is inserted into tissue for 20 min allowing the concentrations of target analytes in the fish muscle to be determined by the extracted amount of analyte and the predetermined sampling rates. Atrazine, carbamazepine, and fluoxetine were detected nonlethally in the low ppb levels within fish muscle, with both laboratory and field-derived results obtained by in vivo SPME-KC comparable to those obtained by lethal sampling followed by tissue liquid extraction. http://pubs.acs.org/doi/abs/10.1021/es201709j EPA Federal Register Activity: Week of August 22 Nothing of interest to the environmental monitoring community was published. |
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