  We revisit the sharp-interface continuum thermodynamics of two-phase
multicomponent fluid systems with interfacial mass. Since the published work is
not fully consistent, we provide a rigorous derivation of the local balance
equations and the entropy production rates, including all relevant steps and
mathematical tools. Special emphasis is put on an axiomatic form of the entropy
principle which, at the same time, allows for an efficient closure process. The
latter builds on an appropriate representation of the entropy production rates,
which is based on structural information being obtained from a more refined
model which includes partial momenta and is given in an appendix. The closure
relations obtained for the one-sided bulk-interface species transfer rates are
further investigated, which leads to a novel model for mass transfer at fluid
interfaces, influenced by the presence of adsorbed surface active agents. We
finally compare our results in detail with the existing literature on continuum
thermodynamics of two-phase multicomponent fluid systems with interfacial mass.
