Exchange of Oxides with Water

Most metal oxides undergo isotopic exchange on the surface, with water at high temperatures (300-900°C.) which is of little interest in biochemical work. 

It should be noted that there is rapid exchange between water vapor and alumina (Whalley and Winter, 1950) but silica does not exchange its oxygen with water below 1000°C. (Hutchinson, 1954). 

A great drawback in many biochemical experiments is the rapid exchange between carbon dioxide and water. Kats and Lapteva (1958) have measured the kinetics of this exchange under various conditions and found it to be complete in approximately 20 hours at 12.5°C. and in 3 hours at 90°. Rothberg and Steinberg (1957) have examined the effect of the shape of the vessel on the rate of isotopic exchange between carbon dioxide and water at 37° C. Mills and Urey (1940) found that carbon dioxide exchanges completely with water in 7 minutes at 30°C. and over an hour at 0°C. 

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