Environmental Chemistry Laboratory Research Articles

Structure and Asymmetry in the Isomeric Conversion of β- to α-Endosulfan

ADVERTISEMENT RETURN TO ISSUECommunicationNEXTStructure and Asymmetry in the Isomeric Conversion of β- to α-EndosulfanWalter F. Schmidt, Cathleen J. Hapeman, James C. Fettinger, Clifford P. Rice, and Susanna BilboulianView Author Information Environmental Chemistry Laboratory, Natural Resources Institute, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742Cite this: J. Agric. Food Chem. 1997, 45, 4, 1023–1026Publication Date (Web):April 16, 1997Publication History Received7 January 1997Published online16 April 1997Published inissue 1 April 1997https://doi.org/10.1021/jf970020tCopyright © 1997 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views605Altmetric-Citations59LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (128 KB) Get e-AlertsSUBJECTS:Conformation,Group theory,Molecular structure,Molecules,Organochlorine Get e-Alerts

Assessment of Chemistry Laboratory Classroom Environments

The Science Laboratory Environment Inventory (SLEI) is a recently developed classroom environment instrument for assessing students' or teachers' perceptions of their science laboratory classroom environment. This paper describes its development and reports on the validation and application of its modified form, the Chemistry Laboratory Environment Inventory (CLEI), with a Singapore secondary school sample. The sample consisted of 1 592 final-year secondary school (i.e. tenth grade) chemistry students from 56 intact classes from 28 randomly selected co-educational government secondary schools in Singapore. Various item and factor analyses supported the reliability and validity of the instrument for assessing students' perceptions of their chemistry laboratory environment specifically in Singapore.

Environment‐‐Attitude Associations in the Chemistry Laboratory Classroom

Abstract Associations between students’ perceptions of their chemistry laboratory classroom environment and their attitudes towards chemistry were investigated using a sample of 1592 final year secondary school chemistry students in 56 classes in 28 randomly‐selected coeducational government schools in Singapore. Students’ perceptions of their chemistry laboratory learning environment were assessed using the Chemistry Laboratory Environment Inventory (CLEI), which is a modified version of the Science Laboratory Environment Inventory (SLEI). The Questionnaire on Chemistry‐related Attitudes (QOCRA), a modified form of the Test of Science‐Related Attitudes (TOSRA), was used to assess the students’ attitudes to chemistry. Environment‐attitude associations were explored using three methods of correlational analysis (simple, multiple and canonical) and two units of statistical analysis (the individual and the class mean). Significant associations were found between the nature of the chemistry laboratory classro...

Soil Selenium: Laboratory Comparisons and Soil/ Backfill Variability

Various analytical methods have been used to determine selenium (Se) in soils, overburden, and plants. Inter-Mountain Laboratories and the Soil and Environmental Chemistry Laboratory at the University of Wyoming conducted a study to determine the variability of soil Se by independently analyzing 20% of the soil/backfill samples from an Abandoned Coal Mine Land research project {open_quotes}Relationship Between Soil Selenium Concentrations and Selenium Uptake by Vegetation on Surface Coal Mine Lands in Wyoming{close_quotes}. The quality control/quality assurance program for this project revealed excellent agreement between the two laboratories. For example, hot water, AB-DTPA, and phosphate extractable Se results from the two laboratories were found to be highly correlated (R{sup 2} {ge} 0.95) by linear regression analyses. Both laboratories followed {open_quotes}Standard Operating Procedures{close_quotes} which included determination of Se by atomic adsorption spectroscopy with hydride generation (Varian HGA-76). Five methods used to determine soil Se (i.e., total Se and four methods of extractable Se - hot water, AB-DTPA, phosphate, and saturated paste) were compared among three cores sampled within a one meter triangle at different sites (native and reclaimed locations) and depths (5 at native and 3 at unclaimed sites). A wide range in the coefficient of variation (CV) was noted (0 tomore » 118%); however, the larger CV`s tended to be grouped at specific sites and depths, and with certain extractants. Of 831 CV`s calculated, only 10 (or 1.2%) were greater than 100%. Average CV`s for mine type and ecological system (i.e., native versus reclaimed) were approximately 25%. Overall, total Se varied the least among the five Se variables followed by phosphate < AB-DTPA < hot water < saturated paste extractable Se.« less

Response to “Comments on ‘Solution Sulfate Chemistry in Three Sulfur-Retentive Hydrandepts’”

Soil Science Society of America JournalVolume 57, Issue 1 p. 293-293 Comment and Letter to the Editor Response to “Comments on ‘Solution Sulfate Chemistry in Three Sulfur-Retentive Hydrandepts’” Jeff Wolt, Jeff Wolt Environmental Chemistry Laboratories DowElanco, Indianapolis, IN, 46268Search for more papers by this authorN. V. Hue, N. V. Hue Dep. of Agronomy and Soil Science, University of Hawaii, Honolulu, HI, 96822Search for more papers by this author Jeff Wolt, Jeff Wolt Environmental Chemistry Laboratories DowElanco, Indianapolis, IN, 46268Search for more papers by this authorN. V. Hue, N. V. Hue Dep. of Agronomy and Soil Science, University of Hawaii, Honolulu, HI, 96822Search for more papers by this author First published: 01 January 1993 https://doi.org/10.2136/sssaj1993.03615995005700010051xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume57, Issue1January-February 1993Pages 293-293 RelatedInformation

Managing an Environmental Chemistry Laboratory for Profit

The implementation of a new analytical method may have a profound impact upon a laboratory depending on the complexity of the method, the difficulty of implementation, and the extent to which the method has been evaluated. This article addresses how a commercial laboratory may be structured in order to most effectively produce analyses of a known and desired quality, how the laboratory at tempts to evaluate methods proposed for routine applications, productivity concerns, and the costing of routine analyses. The organizational structure of a laboratory reveals the focus of the laboratory and where responsibilities lie. The sequence of events in the implementation of a new method begins with a clear statement of the objectives of the analysis, followed by a technical assessment, and concluding with a costing for routine analyses. The events of evaluating and implementing a method to analyze petroleum hydrocarbons for underground storage tank investigations is presented showing the business impact as well as technical considerations. Productivity measures, such as theoretical work area out put evaluation and instrument operation percent capacity, are discussed as tools to be used in a commercial, high volume laboratory. To conclude, the methods typically used to estimate the costs of analyses are presented, and the elements of costing are compared to show the really significant factors affecting profits.

General Procedures for Limit of Detection Calculations in the Industrial Hygiene Chemistry Laboratory

Abstract The limit of detection of an analytical process has been defined to be three standard deviations above the background instrument response. The purpose of this paper is to provide a bridge between this definition and the actual implementation of limit of detection calculations in the industrial hygiene or environmental chemistry laboratory. Methods are illustrated which incorporate into the limit of detection computations the shape of the calibration curve, the accuracy of prediction of the calibration curve, and the variability of instrument responses. The methods presented are widely applicable and can be easily added into existing analytical programs. Burkart, J.A.: General procedures for limit of detection calculations in the industrial hygiene chemistry laboratory.