FY 1985

Solubility of trichlorofluoromethane (F-11) and dichlorodifluoromethane (F-12) in seawater and its relationship to surface concentrations in the North Pacific

Wisegarver, D.P., and J.D. Cline

Deep-Sea Res., 32(1), 97–106, doi: 10.1016/0198-0149(85)90019-6 (1985)

The solubilities of trichlorofluoromethane (F-11) and dichlorodifluoromethane (F-12) were determined in seawater (35 × 10⁻³) and in distilled water from 0 to 30°C. Aqueous concentrations were determined by GC-EC subsequent to equilibration with clean, ambient air containing approximately 200 ppt(v) F-11 and 340 ppt(v) F-12. Our compressed air standard was independently calibrated and we estimate the accuracy and precision of the measurements to be approximately 2%. The temperature dependence of the solubility was determined by fitting the observations to the first three terms of the integrated van't Hoff Equation at a constant 35 × 10 salinity. A comparison of the extant solubility data in seawater with our determinations indicates considerable variability for both F-11 and F-12. Our solubility measurements also are compared to observed concentrations in the surface waters of the eastern, central, and western North Pacific in December 1980, July 1981, June 1982, and March and April 1983, and suggest a supersaturation of 1 to 2% for both fluorocarbons with little or no temperature bias in the surface North Pacific.