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The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium

Includes bibliographical references (leaves 43-44).

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Bibliographic Details
Main Author: Wedeinge, Josef
Other Authors: Brundrit, Geoff
Format: Thesis
Language:English
Published: Department of Oceanography 2014
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access_status_str Open Access
author Wedeinge, Josef
author2 Brundrit, Geoff
author_browse Brundrit, Geoff
Wedeinge, Josef
author_facet Brundrit, Geoff
Wedeinge, Josef
author_sort Wedeinge, Josef
collection Thesis
description Includes bibliographical references (leaves 43-44).
format Thesis
id oai:open.uct.ac.za:11427/6446
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:32:46.693Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Department of Oceanography
publisherStr Department of Oceanography
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/6446 The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium Wedeinge, Josef Brundrit, Geoff Waldron, Howard Applied Marine Science Includes bibliographical references (leaves 43-44). In an attempt to improve the quality of preserving seawater nutrients for delayed analyses, a sample of unfiltered and aged nutrient-depleted seawater was obtained from Marine and Coastal Management (M&CM) and spiked with small different volumes of standard nutrient solutions. These were prepared into 100 mL glass bottles to constitute the lowest, intermediate and highest levels of dissolved inorganic phosphate (0.5, 1.5, 3.0 μM), nitrate (5, 15 and 30 μM) and ammonium (0.5, 1.5, 2.5 μM) that are found in the southern Benguela region. After spiking, the samples were analysed to determine their "true" initial concentrations and immediately quick frozen using liquid nitrogen. A time series analysis (up to seven weeks) was performed by first fast-thawing the samples using a microwave oven and fixing up the nutrients within 20 minutes. Variations in nutrient concentrations did not exceed 7% for phosphate, 4.0% for nitrate at all levels and 8% for ammonium at the intermediate and highest levels, but varied by 19.2% at the lowest level. Statistical tests for significance of the means were made at a = 0.05 level and no difference was found at any level for the nitrate, and the lowest level phosphate. The higher levels of phosphate, and all ammonium were found to be significantly different. Hence, the experimental conditions employed in this paper would not be recommended for the all ammonium and the higher levels of phosphate concentrations. These variations were however not large or regular in pattern but erratic, which suggested that they were not due to microorganisms and optimizing those conditions may well to yield improved results. 2014-08-13T19:44:21Z 2014-08-13T19:44:21Z 2004 Master Thesis Masters MSc http://hdl.handle.net/11427/6446 eng application/pdf Department of Oceanography Faculty of Science University of Cape Town
spellingShingle Applied Marine Science
Wedeinge, Josef
The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
thesis_degree_str Master's
title The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
title_full The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
title_fullStr The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
title_full_unstemmed The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
title_short The effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate, nitrate and ammonium
title_sort effect of quick freezing and fast thawing on stored seawater nutrient concentrations of dissolved inorganic phosphate nitrate and ammonium
topic Applied Marine Science
url http://hdl.handle.net/11427/6446
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