The identifiability of three diffusion properties (diffusion coefficient D, partition coefficient K, and convective mass transfer coefficient hm) from desorption kinetics (or equivalently sorption kinetics) was investigated from a new approximated analytical solution of 1D diffusion coupled with a Robin boundary condition. A generalized least-squares criterion, which extends classical identification techniques, was proposed. The robustness of classical and modified criteria was compared on both experimental and simulated data including different sampling strategies and noise levels. Confidence intervals and bias were calculated for a large set of conditions: desorption levels ranged between 30% and 100% (equilibrium), dilution factors ranged between 10-3 and 10-1, mass Biot numbers ranged between 10-1 and 104, and K values ranged between 10-3 and 5.