Record Details
Non-biological uptake of zinc-65 from a marine algal nutrient medium
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Non-biological uptake of zinc-65 from a marine algal nutrient medium |
| Names |
Tomlinson, Richard Douglas
(creator) Renfro, William C. (advisor) |
| Date Issued | 1970-07-20 (iso8601) |
| Note | Graduation date: 1971 |
| Abstract | The nature and magnitude of experimental errors due to ⁶⁵Zn adsorption by inorganic surfaces was examined in a laboratory system designed to measure ⁶⁵Zn uptake by marine phytoplankton. In the pH range, 6.3±.1 to 7.5±.1, a precipitate formed in the algal nutrient medium selected for the system. To this seawater-base medium, zinc was added only as carrier-free ⁶⁵Zn. The precipitate increased in both volume and tendency for ⁶⁵Zn uptake as the pH increased. At a pH of 7.5±.1 the particles, predominantly orthophosphates, accumulated 70 percent of the ⁶⁵Zn in the medium in 24 hours. It was therefore concluded that ⁶⁵Zn adsorption by undetected precipitates could result in serious errors in measurements of ⁶⁵Zn uptake by marine phytoplankton. Equilibrium of ⁶⁵Zn adsorption by Pyrex glass surfaces was attained between .50 and 2.0 hours elapsed time. Found to be negligible at pH values less that 6.0±.1, such uptake was a linear function of the hydrogen ion concentration in the pH range, 6.7±.1 to 8.2±.1. Pretreatment of the glass surfaces with dimethyldichiorosilane (General Electric "Dry Film") reduced ⁶⁵Zn adsorption by over 80 percent. The relationship between percent ⁶⁵Zn sample adsorption and wetted glass surface area/pipette sample volume was shown to be linear for volumetric pipettes of the size range, 1-15 ml. At a pH of 7.5±.1, ⁶⁵Zn adsorption was negligible for most laboratory glassware, but increased with increased pH. At a pH value of about 8.0, glassware having surface area/sample volume ratios as small as those of 15 and 20 ml volumetric pipettes adsorbed 7 to 11 percent of the contained sample activity. Two prerinses with the sample liquid were required to reduce such errors by a factor of one half. |
| Genre | Thesis/Dissertation |
| Topic | Zinc |
| Identifier | http://hdl.handle.net/1957/29026 |
