Sources of Uncertainty in Stream Nutrient Sampling Below a Point Source

The goal of this study was to determine what aspects of sampling and sample storage could lead to uncertainty when taking samples in a stream below a point source. Sources of uncertainty studied were the locations where the samples were taken to assess if nutrients were adequately mixed within a cross-section, different filtration techniques, dilution errors, analytical uncertainty, and freezing time. Bootstrapping analyses were used to determine whether mixing and dilution errors led to uncertainty, while one-way ANOVAs were used to evaluate filtration techniques and storage time. Sample spikes to determine percent recovery of nutrients and repeat sample analyses are routinely performed as part of the lab quality assurance/quality control plan (QA/QC), and are used here to evaluate analytical uncertainty. Comparison of coefficients of variation (CV) of samples collected within a cross section at four locations, above, at, and below a point source, revealed that mixing of nutrients within a cross section appeared to be different at the different locations. The filtration devices analyzed were an electric pump and a manual syringe. These two devices gave statistically similar results in ammonium, nitrate, and soluble reactive phosphorus concentrations (p \u3e 0.05). Dilution error was determined by comparing seven diluted samples with the original sample with which they were made. Dilutions proved to have the highest uncertainty relative to other treatments. The diluted samples were consistently higher than the original sample for all nutrients and were more variable than lab QA/QC duplicates for ammonium and soluble reactive phosphorus. Analytical uncertainty was found to be less than uncertainty associated with sample collection and storage except for unanticipated protocol failure. For this study, QA/QC data beyond 20% were considered fails, and the samples required reanalysis. In most cases the percent recovery of spiked samples was within 20% and coefficients of variation of samples repeatedly analyzed were much less than 20%. However, ammonium, total nitrogen, and total phosphorus incurred the most failures. Freezing samples appeared to be an adequate storage method. Samples frozen for 12 weeks showed statistically significant declines in total nitrogen (TN) and total phosphorus (TP) concentrations (p \u3c 0.05), however these declines were less than 9% of the initial values. This is within the range of variation seen for analytical duplicates

Undergraduate catalog 2010-12, original

Origina

Undergraduate catalog 2008-10, original

The Undergraduate Catalog for the University of Missouri Columbia has been organized to enhance readability. The initial sections are related to University-wide programs, policies and procedures. The second section provides the listing of academic offerings, organized by the academic units (also may be called colleges or schools) that offer the courses and/or the degrees (major, minor or certificate) that students seek to earn. In addition to the Table of Contents, the Faculty listing and Index at the back of the catalog are invaluable for locating a person or topic quickly. An electronic version is also on the MU web site. Graduate and professional programs (Law, Medicine and Veterinary Medicine) have separate catalogs. -- Page 11.Origina

University of Maine Bulletin, 1998-1999 Undergraduate Catalog, Part 4

Part 4 (of 5) of the University of Maine Catalog for 1998-1999. This portion includes pages 332-447, providing a Key to Abbreviations and the Course Descriptions section

Undergraduate catalog 2008-10, revised

The Undergraduate Catalog for the University of Missouri Columbia has been organized to enhance readability. The initial sections are related to University-wide programs, policies and procedures. The second section provides the listing of academic offerings, organized by the academic units (also may be called colleges or schools) that offer the courses and/or the degrees (major, minor or certificate) that students seek to earn. In addition to the Table of Contents, the Faculty listing and Index at the back of the catalog are invaluable for locating a person or topic quickly. An electronic version is also on the MU web site. Graduate and professional programs (Law, Medicine and Veterinary Medicine) have separate catalogs. -- Page 11.Revised May 2009."Version B.

Undergraduate catalog 2010-12, revised

Revised September 2011

Faculty Senate Bill FSB-2013-11-18-01: University Curriculum Committee

Faculty Senate Bill FSB-2013-11-18-01: University Curriculum Committe

Undergraduate catalog 2006-08, revised

The Undergraduate Catalog for the University of Missouri Columbia has been organized to enhance readability. The initial sections are related to University-wide programs, policies and procedures. The second section provides the listing of academic offerings, organized by the academic units (also may be called colleges or schools) that offer the courses and/or the degrees (major, minor or certificate) that students seek to earn. In addition to the Table of Contents, the Faculty listing and Index at the back of the catalog are invaluable for locating a person or topic quickly. An electronic version is also on the MU web site. Graduate and professional programs (Law, Medicine and Veterinary Medicine) have separate catalogs. -- Page 11.Revised July 2007