Effect of diffusion on measuring oxygen consumption in oxidation reactions with polarographic membrane-covered probe

Abstract

Little is known about the effect of oxygen diffusion on the accuracy of solution oxygen measurements. The effect of O₂ diffusion on the measurement of dissolved O₂ with a polarographic Clark-type membrane-covered electrode was studied during enzymatic and abiotic oxidation of catechol catalyzed by tyrosinase or δ-MnO₂. The depletion of dissolved O₂ during the oxidation of catechol was followed as a function of time in (a) air- or O₂-saturated systems in a vessel completely filled with solution and sealed and (b) air- or O₂-saturated systems with a headspace (the same volume of solution but in a larger vessel). The depletion of dissolved O₂ was also followed after flushing the headspace with N₂. The presence of the headspace had a substantial effect on the measurement of the O₂ consumed by the reaction in air- or O₂-saturated systems. The diffusion of O₂ from the headspace to the solution resulted in an underestimation of the O₂ consumed. In contrast, flushing the headspace with N₂ triggered the diffusion of O₂ from the solution to the headspace, resulting in a very significant overestimation of the O₂ consumed by the reaction. The data indicate that O₂ diffusion-induced problems in solution oxygen measurements by oxygen sensors merit close attention.

References

1. W. W. Umbreit, R. H. Burris and J. F. Stauffer, Manometric and Biochemical Techniques, Burgess, Minneapolis, MN, 5th edn., 1972, pp. 100–110.
2. M. A. Lessler, Methods Biochem. Anal., 1982, 28, 175.
3. R. J. Feigal and B. L. Shapiro, Nature (London), 1979, 278, 276.
4. Y. Matsuo and E. Osada, Biomed. Res., 1981, 2, 705.
5. R. R. Jenkins, R. Friedlander and H. Howald, Int. J. Sports Med., 1984, 5, 11.
6. T. E. Shumacher and J. M. Smuker, Agron. J., 1981, 73, 51.
7. G. A. Garwood, M. M. Mortland and T. J. Pinnavaia, J. Mol. Catal., 1983, 22, 153.
8. H. Claus and Z. Filip, Water Sci. Technol., 1990, 22, 69.
9. J. M. Sarkar, A. Leonowicz and J.-M. Bollag, Soil Biol. Biochem., 1989, 21, 223.
10. A. H. Janovitz-Klapp, F. C. Richard, P. M. Goupy and J. J. Nicolas, J. Agric. Food Chem., 1990, 38, 1437.
11. H. Shindo and P. M. Huang, Nature (London), 1982, 298, 363.
12. H. Shindo and P. M. Huang, Sci. Total Environ., 1992, 117/118, 103.
13. S. Pal, J.-M. Bollag and P. M. Huang, Soil Biol. Biochem., 1994, 26, 813.
14. A. Naidja, P. M. Huang and J.-M. Bollag, Soil Sci. Soc. Am. J., 1998, 62, 188.
15. M. B. McBride, Clays Clay Miner., 1989, 37, 341.
16. R. M. McKenzie, Miner. Mag., 1971, 38, 493.
17. G. S. R. Krishnamurti and P. M. Huang, Can. J. Soil Sci., 1987, 67, 533.
18. A. Naidja, P. M. Huang and J.-M. Bollag, J. Mol. Catal., 1997, 115, 305.
19. Laboratory Supplies and Instruments, Canadawide Scientific, Ottawa, Ontario, 1996, pp. 467–479.
20. K. Lerch, in Metal Ions in Biological Systems, ed. H. Sigel, Marcel Dekker, New York, 1981, vol. 13, pp. 143–186.