Kinetic Approach to the Nonlinear Curve of Bovine Serum Albumin Desorption from Stainless Steel Surfaces

Abstract

The kinetics of the desorption of bovine serum albumin (BSA) from stainless steel particles at various surface coverage values (θ) or at various cleaning temperatures were studied in a plug-flow column fed by a 0.1 M NaOH solution.The desorption curves obtained by plotting the logarithm of the amount of residual BSA against cleaning time was analyzed by using an integrated model for two first-order processes occurring simultaneously.At each θ or temperature, the curve of BSA desorption could be successfully reduced to the sum of two independent and simultaneous first-order processes occurring at different rates.The desorption rate constant (k^f) for the faster-desorbing BSA (BSA^f) was influenced by θ, especially above 0.6.On the other hand, the rate constant (k^s) for the slower-desorbing BSA (BSA^s) was nearly constant when θ was above 0.6.The k^s was approximately 10 to 20 times lower than k^f.The K^f showed an Arrhenius-type temperature dependence.The apparent activation energy (Ea) of k^f was estimated to be 33kJ/mol.The k^f increased by approximately 1.4 times for every 10°C rise in temperature.The proportion of BSA^s to the total amount of adsorbed BSA decreased with increasing cleaning temperatures.