A semipermeable membrane equilibrator for halomethanes in seawater |
| |
Authors: | Wayne Groszko R M Moore |
| |
Institution: | Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 01, Canada |
| |
Abstract: | An equilibrator for sampling the partial pressures of halomethanes in seawater was designed and built, incorporating semipermeable membrane tubing to carry the gas phase. The equilibrator was tested for its ability to equilibrate chloromethane, bromomethane, iodomethane, and CFC-11. The residence time required for these halomethanes to equilibrate in the tubing (30 to 60 s) was determined experimentally. In a laboratory test, concentrations calculated from equilibrator measurements and based on published solubility values were found to differ by 6% to 16% from concentrations measured with a purge-and-trap apparatus, but uncertainties in the solubility values are likely to contribute significantly to the differences. In a comparison at sea, no significant difference was found between the semipermeable membrane equilibrator and another, more conventional equilibrator, except a 1.3% difference for CFC-11. This study demonstrates the feasibility of using semipermeable membranes in this and related applications. |
| |
Keywords: | equilibrator semipermeable membrane methyl chloride methyl bromide methyl iodide CFC-11 |
本文献已被 ScienceDirect 等数据库收录! |
|