Abstract: Described are apparatus and methods allowing measurement of adsorption and desorption of analytes with membranes or resins directly using increased lateral mass transport. Such increased lateral mass transport may be accomplished through the incorporation of a porous media, such as a fibrous bed or a concentrated bed of spheres, into said flow cell. Further described is a method of determining if a flow cell would benefit from increased lateral mass transport comprising comparing the rate of surface reaction to the mass transfer coefficient for a given analyte. The detection method for the measurement of adsorption and desorption of analytes may be based on the evanescent wave phenomenon at total internal reflection, such as surface plasmon resonance (SPR), critical angle refractometry, total internal reflection fluorescence (TIRF), total internal reflection phosphorescence, total internal reflection light scattering, optical waveguide fluorescence, evanescent wave.

Abstract: Described are methods allowing measurement of adsorption and desorption of analytes with membranes or resins directly using surface plasmon resonance (SPR). Also described are methods for assembling intact resins or membranes on SPR surfaces. Such methods provide estimates of mass-action ion-exchange adsorption and desorption rates accounting for steric (?) and characteristic charge (?) effects. The methods further permit accurate estimation of rate constants for uniform adsorption of a homogeneous analyte solution on homogeneous adsorptive sites distributed heterogeneously in space, relative to the planar boundary. Solutions are obtained for locally porous media and solid spheres. The methods are extendible to other media and heterogeneous adsorptive sites.