Abstract
Three experimental methodologies that aim at giving general guidelines for a robust joint determination of the diffusion and the partition coefficients on polymeric food contact materials are presented and compared: One based on optimal experimental design, one based on taking samples at equally spaced concentrations, and one based on taking samples at equally spaced times. The three methodologies are tested for a wide range of mass transfer speeds (D between 0.0005 and 5 10(-13) m(2) s(-1)) and equilibrium conditions (K between 1 and 100), that mimic the behavior of high- and low-barrier polymers, under constraints that affect the sampling technique (global or local measuring), maximum sampling number (3-5), minimum spacing between samples and maximum experiment time. Results show that even with slow kinetics (D approximate to 5 center dot 10(-15) m(2) s(-1)), the joint determination is feasible under certain conditions, within a reasonable experiment running time and a lower uncertainty than the current recommendations given by the EU directive.