抄録
The kinetics of desorption of bovine serum albumin (BSA) from ozone-modified alumina (Al2O3) particles during caustic alkali cleaning was studied. Al2O3 particles were treated with gaseous ozone generated from pure oxygen at concentrations of 0.05 to 0.2 vol%. As a result of ozone treatment, the absolute values of the surface charge density of Al2O3 particles decreased, with slight shifts in the apparent points of zero charge to the points corresponding to more acidic pH values, and the amount of BSA adsorbed on Al2O3 also decreased. The desorption curve of BSA, which was obtained by plotting the logarithm of the amount of residual BSA versus cleaning time, could be analyzed by the integrated desorption kinetic model which describes two simultaneous first-order reactions. The desorption curves of BSA from non-ozone-treated and ozone-treated particles could apparently be reduced to the sum of two independent first-order reactions occurring simultaneously at different rates, suggesting that a faster-desorbing and slower-desorbing BSA species were present on Al2O3 surfaces. It was found that the effect of ozone modification of Al2O3 surfaces was reflected both by an increase in the desorption rate constant, by one order of magnitude, of a slower-desorbing BSA species and by a decrease in its relative abundance on Al2O3 surfaces.
