Record Details
Development of an autonomous in-situ instrument for long-term monitoring of Cu(II) in the marine environment
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Development of an autonomous in-situ instrument for long-term monitoring of Cu(II) in the marine environment |
| Names |
Holm, Christopher E.
(creator) Zanna, Chase (advisor) |
| Date Issued | 2006-12-08 (iso8601) |
| Internet Media Type | application/pdf |
| Note | Graduation date: 2007 |
| Abstract | An autonomous, in-situ instrument was developed to detect dissolved copper in seawater, suitable for deployment on time scales from weeks to months. A commercially available in-situ nitrate analyzer (YSI 9600) was adapted to measure copper (II) in seawater by chemiluminescence. Modifications included construction of a photomultiplier (PMT) based detector and flow-cell, the use of more chemically resistant plastics for parts in contact with the reagents, addition of an in-line acidification step and optimization of the method and flow parameters. Filtration to 0.45μm and acidification online (pH ~1.7) produces a measurement of total dissolved Cu(II). Calibration is achieved by periodically analyzing ligand-stabilized seawater standard and blank solutions stored at pH 8 and acidified online. Micro solenoid pumps take in sample and dispense reagent, standard, and blank solutions, which are stored in 1L plastic bags. All waste is collected in two 5L bags. In-situ, the instrument has an average detection limit of 0.8(3) nM, a sample precision of 7%, and an accuracy, assessed over all deployments, of 17%. The instrument is capable of functioning autonomously for 25 days sampling every hour and calibrating every six hours, with reagent consumption being the limiting factor. |
| Genre | Thesis |
| Topic | Copper |
| Identifier | http://hdl.handle.net/1957/3773 |
