Jermann S Ortner F Rajendran A Mazzotti M 2015 We investigate the system consisting of phenetole (PNT) and 4-tert-butylphenol (TBP) in methanol-water (63:37 v:v) on a Zorbax 300SB-C18 column by characterising single component isotherms, by performing a large number of binary experiments of different types and by describing the experiments through simulations carried out using a novel, rather powerful competitive adsorption isotherm, that we call the generalized bi-Langmuir isotherm. This system is of great interest because it was previously reported to yield a new type of transition in nonlinear chromatography, the so-called delta-shock. Such transition had been discovered earlier through a theoretical analysis and confirmed by detailed simulations. The initial aim of this work was to reach a satisfactory agreement between delta-shock experiments and corresponding numerical simulations. In the course of this work however, a number of inconsistencies in the interpretation of the previous experimental results were highlighted and explained. This led to a new experimental campaign, which is reported here and has allowed to reach two important conclusions: (1) The binary system PNT-TBP mentioned above does not exhibit a delta-shock; the spike in the UV profile, which has previously been interpreted as an experimental evidence of the delta-shock, results from liquid-liquid phase separation within the chromatographic column. (2) The same system exhibits a rather peculiar behavior in breakthrough and displacement experiments, which could be well described using the generalized bi-Langmuir isotherm. https://sonar.ch/global/documents/143396 eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.chroma.2015.11.003 info:eu-repo/semantics/altIdentifier/pmid/26614175 Journal of chromatography. A. - 2015 Delta-shock Non-linear chromatography Adsorption Chemistry Techniques, Analytical Chromatography Computer Simulation Methanol Phenols Phenyl Ethers Water Absence of experimental evidence of a delta-shock in the system phenetole and 4-tert-butylphenol on Zorbax 300SB-C18. http://purl.org/coar/resource_type/c_6501