The estimation of reliable adsorption / equilibrium data are crucial for researchers in a wide range of fields such as analytical chemistry, biochemistry, chemical engineering, pharmacology and pharmacokinetics. Traditionally, equilibrium data are simply estimated from the statistically best-fitted model to adsorption data; but there are many dangerous pitfalls on this road. We have therefore recently improved several methods for adsorption isotherm determinations. As example, the accuracy of generating adsorption data by the elution by characteristic points (ECP) method was increased considerably by a new experimental approach that eliminated the post-loop dispersion; the method was also expanded to cover more different general types of adsorption isotherms than before. We have also made important improvements on the processing and evaluation of the data based on a firm theoretical basis. In this context, a new numerical tool was developed, calculation of the adsorption energy distribution (AED) allowing the estimation of the degree of heterogeneity of the interaction prior to the rival model fit. This concept has also been transposed to modern biosensors such as surface plasmon resonance (SPR) technology and continuous flow quartz crystal microbalance (QCM). We have utilized the improvements of generating and evaluation adsorption data to reveal more detailed information about molecular interactions in systems aimed at analytical and preparative separations and to understand better bio-molecular interactions derived from modern biosensors. This is a contribution from the Fundamental Separation Science Group in Karlstad www.separationscience.se